:Hacker Folklore:

This appendix contains several legends and fables that illuminate the meaning of various entries in the lexicon.

The Meaning of `Hack':

"The word {hack} doesn't really have 69 different meanings", according to MIT hacker Phil Agre. "In fact, {hack} has only one meaning, an extremely subtle and profound one which defies articulation. Which connotation is implied by a given use of the word depends in similarly profound ways on the context. Similar remarks apply to a couple of other hacker words, most notably {random}."

Hacking might be characterized as `an appropriate application of ingenuity'. Whether the result is a quick-and-dirty patchwork job or a carefully crafted work of art, you have to admire the cleverness that went into it.

An important secondary meaning of {hack} is `a creative practical joke'. This kind of hack is easier to explain to non-hackers than the programming kind. Of course, some hacks have both natures; see the lexicon entries for {pseudo} and {kgbvax}. But here are some examples of pure practical jokes that illustrate the hacking spirit:

In 1961, students from Caltech (California Institute of Technology, in Pasadena) hacked the Rose Bowl football game. One student posed as a reporter and `interviewed' the director of the University of Washington card stunts (such stunts involve people in the stands who hold up colored cards to make pictures). The reporter learned exactly how the stunts were operated, and also that the director would be out to dinner later.

While the director was eating, the students (who called themselves the `Fiendish Fourteen') picked a lock and stole a blank direction sheet for the card stunts. They then had a printer run off 2300 copies of the blank. The next day they picked the lock again and stole the master plans for the stunts -- large sheets of graph paper colored in with the stunt pictures. Using these as a guide, they made new instructions for three of the stunts on the duplicated blanks. Finally, they broke in once more, replacing the stolen master plans and substituting the stack of diddled instruction sheets for the original set.

The result was that three of the pictures were totally different. Instead of `WASHINGTON', the word ``CALTECH' was flashed. Another stunt showed the word `HUSKIES', the Washington nickname, but spelled it backwards. And what was supposed to have been a picture of a husky instead showed a beaver. (Both Caltech and MIT use the beaver --- nature's engineer -- as a mascot.)

After the game, the Washington faculty athletic representative said: "Some thought it ingenious; others were indignant." The Washington student body president remarked: "No hard feelings, but at the time it was unbelievable. We were amazed."

This is now considered a classic hack, particularly because revising the direction sheets constituted a form of programming.

Here is another classic hack:

On November 20, 1982, MIT hacked the Harvard-Yale football game. Just after Harvard's second touchdown against Yale, in the first quarter, a small black ball popped up out of the ground at the 40-yard line, and grew bigger, and bigger, and bigger. The letters `MIT' appeared all over the ball. As the players and officials stood around gawking, the ball grew to six feet in diameter and then burst with a bang and a cloud of white smoke.

The "Boston Globe" later reported: "If you want to know the truth, MIT won The Game."

The prank had taken weeks of careful planning by members of MIT's Delta Kappa Epsilon fraternity. The device consisted of a weather balloon, a hydraulic ram powered by Freon gas to lift it out of the ground, and a vacuum-cleaner motor to inflate it. They made eight separate expeditions to Harvard Stadium between 1 and 5 A.M., locating an unused 110-volt circuit in the stadium and running buried wires from the stadium circuit to the 40-yard line, where they buried the balloon device. When the time came to activate the device, two fraternity members had merely to flip a circuit breaker and push a plug into an outlet.

This stunt had all the earmarks of a perfect hack: surprise, publicity, the ingenious use of technology, safety, and harmlessness. The use of manual control allowed the prank to be timed so as not to disrupt the game (it was set off between plays, so the outcome of the game would not be unduly affected). The perpetrators had even thoughtfully attached a note to the balloon explaining that the device was not dangerous and contained no explosives.

Harvard president Derek Bok commented: "They have an awful lot of clever people down there at MIT, and they did it again." President Paul E. Gray of MIT said: "There is absolutely no truth to the rumor that I had anything to do with it, but I wish there were."

The hacks above are verifiable history; they can be proved to have happened. Many other classic-hack stories from MIT and elsewhere, though retold as history, have the characteristics of what Jan Brunvand has called `urban folklore' (see {FOAF}). Perhaps the best known of these is the legend of the infamous trolley-car hack, an alleged incident in which engineering students are said to have welded a trolley car to its tracks with thermite. Numerous versions of this have been recorded from the 1940s to the present, most set at MIT but at least one very detailed version set at CMU.

Brian Leibowitz has researched MIT hacks both real and mythical extensively; the interested reader is referred to his delightful pictorial compendium "The Journal of the Institute for Hacks, Tomfoolery, and Pranks" (MIT Museum, 1990; ISBN 0-917027-03-5). The Institute has a World Wide Web page at http://fishwrap.mit.edu/Hacks/Gallery.html.

Finally, here is a story about one of the classic computer hacks.

Back in the mid-1970s, several of the system support staff at Motorola discovered a relatively simple way to crack system security on the Xerox CP-V timesharing system. Through a simple programming strategy, it was possible for a user program to trick the system into running a portion of the program in `master mode' (supervisor state), in which memory protection does not apply. The program could then poke a large value into its `privilege level' byte (normally write-protected) and could then proceed to bypass all levels of security within the file-management system, patch the system monitor, and do numerous other interesting things. In short, the barn door was wide open.

Motorola quite properly reported this problem to Xerox via an official `level 1 SIDR' (a bug report with an intended urgency of `needs to be fixed yesterday'). Because the text of each SIDR was entered into a database that could be viewed by quite a number of people, Motorola followed the approved procedure: they simply reported the problem as `Security SIDR', and attached all of the necessary documentation, ways-to-reproduce, etc.

The CP-V people at Xerox sat on their thumbs; they either didn't realize the severity of the problem, or didn't assign the necessary operating-system-staff resources to develop and distribute an official patch.

Months passed. The Motorola guys pestered their Xerox field-support rep, to no avail. Finally they decided to take direct action, to demonstrate to Xerox management just how easily the system could be cracked and just how thoroughly the security safeguards could be subverted.

They dug around in the operating-system listings and devised a thoroughly devilish set of patches. These patches were then incorporated into a pair of programs called `Robin Hood' and `Friar Tuck'. Robin Hood and Friar Tuck were designed to run as `ghost jobs' (daemons, in Unix terminology); they would use the existing loophole to subvert system security, install the necessary patches, and then keep an eye on one another's statuses in order to keep the system operator (in effect, the superuser) from aborting them.

One fine day, the system operator on the main CP-V software development system in El Segundo was surprised by a number of unusual phenomena. These included the following:

* Tape drives would rewind and dismount their tapes in the middle of a job. * Disk drives would seek back and forth so rapidly that they would attempt to walk across the floor (see {walking drives}). * The card-punch output device would occasionally start up of itself and punch a {lace card}. These would usually jam in the punch. * The console would print snide and insulting messages from Robin Hood to Friar Tuck, or vice versa. * The Xerox card reader had two output stackers; it could be instructed to stack into A, stack into B, or stack into A (unless a card was unreadable, in which case the bad card was placed into stacker B). One of the patches installed by the ghosts added some code to the card-reader driver... after reading a card, it would flip over to the opposite stacker. As a result, card decks would divide themselves in half when they were read, leaving the operator to recollate them manually.

Naturally, the operator called in the operating-system developers. They found the bandit ghost jobs running, and {gun}ned them... and were once again surprised. When Robin Hood was gunned, the following sequence of events took place:

!X id1

id1: Friar Tuck... I am under attack! Pray save me! id1: Off (aborted)

id2: Fear not, friend Robin! I shall rout the Sheriff of Nottingham's men!

id1: Thank you, my good fellow!

Each ghost-job would detect the fact that the other had been killed, and would start a new copy of the recently slain program within a few milliseconds. The only way to kill both ghosts was to kill them simultaneously (very difficult) or to deliberately crash the system.

Finally, the system programmers did the latter -- only to find that the bandits appeared once again when the system rebooted! It turned out that these two programs had patched the boot-time OS image (the kernel file, in Unix terms) and had added themselves to the list of programs that were to be started at boot time (this is similar to the way MS-DOS viruses propagate).

The Robin Hood and Friar Tuck ghosts were finally eradicated when the system staff rebooted the system from a clean boot-tape and reinstalled the monitor. Not long thereafter, Xerox released a patch for this problem.

It is alleged that Xerox filed a complaint with Motorola's management about the merry-prankster actions of the two employees in question. It is not recorded that any serious disciplinary action was taken against either of them.

TV Typewriters: A Tale of Hackish Ingenuity

Here is a true story about a glass tty: One day an MIT hacker was in a motorcycle accident and broke his leg. He had to stay in the hospital quite a while, and got restless because he couldn't {hack}. Two of his friends therefore took a terminal and a modem for it to the hospital, so that he could use the computer by telephone from his hospital bed.

Now this happened some years before the spread of home computers, and computer terminals were not a familiar sight to the average person. When the two friends got to the hospital, a guard stopped them and asked what they were carrying. They explained that they wanted to take a computer terminal to their friend who was a patient.

The guard got out his list of things that patients were permitted to have in their rooms: TV, radio, electric razor, typewriter, tape player, ... no computer terminals. Computer terminals weren't on the list, so the guard wouldn't let it in. Rules are rules, you know. (This guard was clearly a {droid}.)

Fair enough, said the two friends, and they left again. They were frustrated, of course, because they knew that the terminal was as harmless as a TV or anything else on the list... which gave them an idea.

The next day they returned, and the same thing happened: a guard stopped them and asked what they were carrying. They said: "This is a TV typewriter!" The guard was skeptical, so they plugged it in and demonstrated it. "See? You just type on the keyboard and what you type shows up on the TV screen." Now the guard didn't stop to think about how utterly useless a typewriter would be that didn't produce any paper copies of what you typed; but this was clearly a TV typewriter, no doubt about it. So he checked his list: "A TV is all right, a typewriter is all right ... okay, take it on in!"

[Historical note: Many years ago, "Popular Electronics" published solder-it-yourself plans for a TV typewriter. Despite the essential uselessness of the device, it was an enormously popular project. Steve Ciarcia, the man behind "Byte" magazine's "Circuit Cellar" feature, resurrected this ghost in one of his books of the early 1980s. He ascribed its popularity (no doubt correctly) to the feeling of power the builder could achieve by being able to decide himself what would be shown on the TV. --ESR]

[Antihistorical note: On September 23rd, 1992, the L.A. Times ran the following bit of filler:

Solomon Waters of Altadena, a 6-year-old first-grader, came home from his first day of school and excitedly told his mother how he had written on "a machine that looks like a computer -- but without the TV screen." She asked him if it could have been a "typewriter." "Yeah! Yeah!" he said. "That's what it was called."

I have since investigated this matter and determined that many of today's teenagers have never seen a slide rule, either.... -- ESR]

A Story About `Magic':

Some years ago, I (GLS) was snooping around in the cabinets that housed the MIT AI Lab's PDP-10, and noticed a little switch glued to the frame of one cabinet. It was obviously a homebrew job, added by one of the lab's hardware hackers (no one knows who).

You don't touch an unknown switch on a computer without knowing what it does, because you might crash the computer. The switch was labeled in a most unhelpful way. It had two positions, and scrawled in pencil on the metal switch body were the words `magic' and `more magic'. The switch was in the `more magic' position.

I called another hacker over to look at it. He had never seen the switch before either. Closer examination revealed that the switch had only one wire running to it! The other end of the wire did disappear into the maze of wires inside the computer, but it's a basic fact of electricity that a switch can't do anything unless there are two wires connected to it. This switch had a wire connected on one side and no wire on its other side.

It was clear that this switch was someone's idea of a silly joke. Convinced by our reasoning that the switch was inoperative, we flipped it. The computer instantly crashed.

Imagine our utter astonishment. We wrote it off as coincidence, but nevertheless restored the switch to the `more magic' position before reviving the computer.

A year later, I told this story to yet another hacker, David Moon as I recall. He clearly doubted my sanity, or suspected me of a supernatural belief in the power of this switch, or perhaps thought I was fooling him with a bogus saga. To prove it to him, I showed him the very switch, still glued to the cabinet frame with only one wire connected to it, still in the `more magic' position. We scrutinized the switch and its lone connection, and found that the other end of the wire, though connected to the computer wiring, was connected to a ground pin. That clearly made the switch doubly useless: not only was it electrically nonoperative, but it was connected to a place that couldn't affect anything anyway. So we flipped the switch.

The computer promptly crashed.

This time we ran for Richard Greenblatt, a long-time MIT hacker, who was close at hand. He had never noticed the switch before, either. He inspected it, concluded it was useless, got some diagonal cutters and {dike}d it out. We then revived the computer and it has run fine ever since.

We still don't know how the switch crashed the machine. There is a theory that some circuit near the ground pin was marginal, and flipping the switch changed the electrical capacitance enough to upset the circuit as millionth-of-a-second pulses went through it. But we'll never know for sure; all we can really say is that the switch was {magic}.

I still have that switch in my basement. Maybe I'm silly, but I usually keep it set on `more magic'.

1994: Another explanation of this story has since been offered. Note that the switch body was metal. Suppose that the non-connected side of the switch was connected to the switch body (usually the body is connected to a separate earth lug, but there are exceptions). The body is connected to the computer case, which is, presumably, grounded. Now the circuit ground within the machine isn't necessarily at the same potential as the case ground, so flipping the switch connected the circuit ground to the case ground, causing a voltage drop/jump which reset the machine. This was probably discovered by someone who found out the hard way that there was a potential difference between the two, and who then wired in the switch as a joke.

AI Koans:

These are some of the funniest examples of a genre of jokes told at the MIT AI Lab about various noted hackers. The original koans were composed by Danny Hillis. In reading these, it is at least useful to know that Minsky, Sussman, and Drescher are AI researchers of note, that Tom Knight was one of the Lisp machine's principal designers, and that David Moon wrote much of Lisp Machine Lisp.

* * *

A novice was trying to fix a broken Lisp machine by turning the power off and on.

Knight, seeing what the student was doing, spoke sternly: "You cannot fix a machine by just power-cycling it with no understanding of what is going wrong."

Knight turned the machine off and on.

The machine worked.

* * *

One day a student came to Moon and said: "I understand how to make a better garbage collector. We must keep a reference count of the pointers to each cons."

Moon patiently told the student the following story:

"One day a student came to Moon and said: `I understand how to make a better garbage collector...

[Ed. note: Pure reference-count garbage collectors have problems with circular structures that point to themselves.]

* * *

In the days when Sussman was a novice, Minsky once came to him as he sat hacking at the PDP-6.

"What are you doing?", asked Minsky.

"I am training a randomly wired neural net to play Tic-Tac-Toe" Sussman replied.

"Why is the net wired randomly?", asked Minsky.

"I do not want it to have any preconceptions of how to play", Sussman said.

Minsky then shut his eyes.

"Why do you close your eyes?", Sussman asked his teacher.

"So that the room will be empty."

At that moment, Sussman was enlightened.

* * *

A disciple of another sect once came to Drescher as he was eating his morning meal.

"I would like to give you this personality test", said the outsider, "because I want you to be happy."

Drescher took the paper that was offered him and put it into the toaster, saying: "I wish the toaster to be happy, too."

OS and JEDGAR:

This story says a lot about the ITS ethos.

On the ITS system there was a program that allowed you to see what was being printed on someone else's terminal. It spied on the other guy's output by examining the insides of the monitor system. The output spy program was called OS. Throughout the rest of the computer science (and at IBM too) OS means `operating system', but among old-time ITS hackers it almost always meant `output spy'.

OS could work because ITS purposely had very little in the way of `protection' that prevented one user from trespassing on another's areas. Fair is fair, however. There was another program that would automatically notify you if anyone started to spy on your output. It worked in exactly the same way, by looking at the insides of the operating system to see if anyone else was looking at the insides that had to do with your output. This `counterspy' program was called JEDGAR (a six-letterism pronounced as two syllables: /jed'gr/), in honor of the former head of the FBI.

But there's more. JEDGAR would ask the user for `license to kill'. If the user said yes, then JEDGAR would actually {gun} the job of the {luser} who was spying. Unfortunately, people found that this made life too violent, especially when tourists learned about it. One of the systems hackers solved the problem by replacing JEDGAR with another program that only pretended to do its job. It took a long time to do this, because every copy of JEDGAR had to be patched. To this day no one knows how many people never figured out that JEDGAR had been defanged.

Interestingly, there is still a security module named JEDGAR alive as of late 1994 -- in the Unisys MCP for large systems. It is unknown to us whether the name is tribute or independent invention.

The Story of Mel, a Real Programmer:

This was posted to Usenet by its author, Ed Nather (utastro!nather), on May 21, 1983.

A recent article devoted to the *macho* side of programming made the bald and unvarnished statement:

Real Programmers write in FORTRAN.

Maybe they do now, in this decadent era of Lite beer, hand calculators, and "user-friendly" software but back in the Good Old Days, when the term "software" sounded funny and Real Computers were made out of drums and vacuum tubes, Real Programmers wrote in machine code. Not FORTRAN. Not RATFOR. Not, even, assembly language. Machine Code. Raw, unadorned, inscrutable hexadecimal numbers. Directly.

Lest a whole new generation of programmers grow up in ignorance of this glorious past, I feel duty-bound to describe, as best I can through the generation gap, how a Real Programmer wrote code. I'll call him Mel, because that was his name.

I first met Mel when I went to work for Royal McBee Computer Corp., a now-defunct subsidiary of the typewriter company. The firm manufactured the LGP-30, a small, cheap (by the standards of the day) drum-memory computer, and had just started to manufacture the RPC-4000, a much-improved, bigger, better, faster -- drum-memory computer. Cores cost too much, and weren't here to stay, anyway. (That's why you haven't heard of the company, or the computer.)

I had been hired to write a FORTRAN compiler for this new marvel and Mel was my guide to its wonders. Mel didn't approve of compilers.

"If a program can't rewrite its own code", he asked, "what good is it?"

Mel had written, in hexadecimal, the most popular computer program the company owned. It ran on the LGP-30 and played blackjack with potential customers at computer shows. Its effect was always dramatic. The LGP-30 booth was packed at every show, and the IBM salesmen stood around talking to each other. Whether or not this actually sold computers was a question we never discussed.

Mel's job was to re-write the blackjack program for the RPC-4000. (Port? What does that mean?) The new computer had a one-plus-one addressing scheme, in which each machine instruction, in addition to the operation code and the address of the needed operand, had a second address that indicated where, on the revolving drum, the next instruction was located.

In modern parlance, every single instruction was followed by a GO TO! Put *that* in Pascal's pipe and smoke it.

Mel loved the RPC-4000 because he could optimize his code: that is, locate instructions on the drum so that just as one finished its job, the next would be just arriving at the "read head" and available for immediate execution. There was a program to do that job, an "optimizing assembler", but Mel refused to use it.

"You never know where it's going to put things", he explained, "so you'd have to use separate constants".

It was a long time before I understood that remark. Since Mel knew the numerical value of every operation code, and assigned his own drum addresses, every instruction he wrote could also be considered a numerical constant. He could pick up an earlier "add" instruction, say, and multiply by it, if it had the right numeric value. His code was not easy for someone else to modify.

I compared Mel's hand-optimized programs with the same code massaged by the optimizing assembler program, and Mel's always ran faster. That was because the "top-down" method of program design hadn't been invented yet, and Mel wouldn't have used it anyway. He wrote the innermost parts of his program loops first, so they would get first choice of the optimum address locations on the drum. The optimizing assembler wasn't smart enough to do it that way.

Mel never wrote time-delay loops, either, even when the balky Flexowriter required a delay between output characters to work right. He just located instructions on the drum so each successive one was just *past* the read head when it was needed; the drum had to execute another complete revolution to find the next instruction. He coined an unforgettable term for this procedure. Although "optimum" is an absolute term, like "unique", it became common verbal practice to make it relative: "not quite optimum" or "less optimum" or "not very optimum". Mel called the maximum time-delay locations the "most pessimum".

After he finished the blackjack program and got it to run ("Even the initializer is optimized", he said proudly), he got a Change Request from the sales department. The program used an elegant (optimized) random number generator to shuffle the "cards" and deal from the "deck", and some of the salesmen felt it was too fair, since sometimes the customers lost. They wanted Mel to modify the program so, at the setting of a sense switch on the console, they could change the odds and let the customer win.

Mel balked. He felt this was patently dishonest, which it was, and that it impinged on his personal integrity as a programmer, which it did, so he refused to do it. The Head Salesman talked to Mel, as did the Big Boss and, at the boss's urging, a few Fellow Programmers. Mel finally gave in and wrote the code, but he got the test backwards, and, when the sense switch was turned on, the program would cheat, winning every time. Mel was delighted with this, claiming his subconscious was uncontrollably ethical, and adamantly refused to fix it.

After Mel had left the company for greener pa$ture$, the Big Boss asked me to look at the code and see if I could find the test and reverse it. Somewhat reluctantly, I agreed to look. Tracking Mel's code was a real adventure.

I have often felt that programming is an art form, whose real value can only be appreciated by another versed in the same arcane art; there are lovely gems and brilliant coups hidden from human view and admiration, sometimes forever, by the very nature of the process. You can learn a lot about an individual just by reading through his code, even in hexadecimal. Mel was, I think, an unsung genius.

Perhaps my greatest shock came when I found an innocent loop that had no test in it. No test. *None*. Common sense said it had to be a closed loop, where the program would circle, forever, endlessly. Program control passed right through it, however, and safely out the other side. It took me two weeks to figure it out.

The RPC-4000 computer had a really modern facility called an index register. It allowed the programmer to write a program loop that used an indexed instruction inside; each time through, the number in the index register was added to the address of that instruction, so it would refer to the next datum in a series. He had only to increment the index register each time through. Mel never used it.

Instead, he would pull the instruction into a machine register, add one to its address, and store it back. He would then execute the modified instruction right from the register. The loop was written so this additional execution time was taken into account --- just as this instruction finished, the next one was right under the drum's read head, ready to go. But the loop had no test in it.

The vital clue came when I noticed the index register bit, the bit that lay between the address and the operation code in the instruction word, was turned on --- yet Mel never used the index register, leaving it zero all the time. When the light went on it nearly blinded me.

He had located the data he was working on near the top of memory --- the largest locations the instructions could address --- so, after the last datum was handled, incrementing the instruction address would make it overflow. The carry would add one to the operation code, changing it to the next one in the instruction set: a jump instruction. Sure enough, the next program instruction was in address location zero, and the program went happily on its way.

I haven't kept in touch with Mel, so I don't know if he ever gave in to the flood of change that has washed over programming techniques since those long-gone days. I like to think he didn't. In any event, I was impressed enough that I quit looking for the offending test, telling the Big Boss I couldn't find it. He didn't seem surprised.

When I left the company, the blackjack program would still cheat if you turned on the right sense switch, and I think that's how it should be. I didn't feel comfortable hacking up the code of a Real Programmer.

This is one of hackerdom's great heroic epics, free verse or no. In a few spare images it captures more about the esthetics and psychology of hacking than all the scholarly volumes on the subject put together. For an opposing point of view, see the entry for {Real Programmer}.

[1992 postscript -- the author writes: "The original submission to the net was not in free verse, nor any approximation to it -- it was straight prose style, in non-justified paragraphs. In bouncing around the net it apparently got modified into the `free verse' form now popular. In other words, it got hacked on the net. That seems appropriate, somehow." The author adds that he likes the `free-verse' version better...]

:A Portrait of J. Random Hacker: ********************************

This profile reflects detailed comments on an earlier `trial balloon' version from about a hundred Usenet respondents. Where comparatives are used, the implicit `other' is a randomly selected segment of the non-hacker population of the same size as hackerdom.

An important point: Except in some relatively minor respects such as slang vocabulary, hackers don't get to be the way they are by imitating each other. Rather, it seems to be the case that the combination of personality traits that makes a hacker so conditions one's outlook on life that one tends to end up being like other hackers whether one wants to or not (much as bizarrely detailed similarities in behavior and preferences are found in genetic twins raised separately).

General Appearance:

Intelligent. Scruffy. Intense. Abstracted. Surprisingly for a sedentary profession, more hackers run to skinny than fat; both extremes are more common than elsewhere. Tans are rare.

Dress:

Casual, vaguely post-hippie; T-shirts, jeans, running shoes, Birkenstocks (or bare feet). Long hair, beards, and moustaches are common. High incidence of tie-dye and intellectual or humorous `slogan' T-shirts (only rarely computer related; that would be too obvious).

A substantial minority prefers `outdoorsy' clothing -- hiking boots ("in case a mountain should suddenly spring up in the machine room", as one famous parody put it), khakis, lumberjack or chamois shirts, and the like.

Very few actually fit the "National Lampoon" Nerd stereotype, though it lingers on at MIT and may have been more common before 1975. At least since the late Seventies backpacks have been more common than briefcases, and the hacker `look' has been more whole-earth than whole-polyester.

Hackers dress for comfort, function, and minimal maintenance hassles rather than for appearance (some, perhaps unfortunately, take this to extremes and neglect personal hygiene). They have a very low tolerance of suits and other `business' attire; in fact, it is not uncommon for hackers to quit a job rather than conform to a dress code.

Female hackers almost never wear visible makeup, and many use none at all.

Reading Habits:

Omnivorous, but usually includes lots of science and science fiction. The typical hacker household might subscribe to "Analog", "Scientific American", "Whole-Earth Review", and "Smithsonian" (most hackers ignore "Wired" and other self-consciously `cyberpunk' magazines, considering them {wannabee} fodder). Hackers often have a reading range that astonishes liberal arts people but tend not to talk about it as much. Many hackers spend as much of their spare time reading as the average American burns up watching TV, and often keep shelves and shelves of well-thumbed books in their homes.

Other Interests:

Some hobbies are widely shared and recognized as going with the culture: science fiction, music, medievalism (in the active form practiced by the Society for Creative Anachronism and similar organizations), chess, go, backgammon, wargames, and intellectual games of all kinds. (Role-playing games such as Dungeons and Dragons used to be extremely popular among hackers but they lost a bit of their luster as they moved into the mainstream and became heavily commercialized. More recently, "Magic: The Gathering" has been widely popular among hackers.) Logic puzzles. Ham radio. Other interests that seem to correlate less strongly but positively with hackerdom include linguistics and theater teching.

Physical Activity and Sports:

Many (perhaps even most) hackers don't follow or do sports at all and are determinedly anti-physical. Among those who do, interest in spectator sports is low to non-existent; sports are something one *does*, not something one watches on TV.

Further, hackers avoid most team sports like the plague. Volleyball was long a notable exception, perhaps because it's non-contact and relatively friendly; Ultimate Frisbee has become quite popular for similar reasons. Hacker sports are almost always primarily self-competitive ones involving concentration, stamina, and micromotor skills: martial arts, bicycling, auto racing, kite flying, hiking, rock climbing, aviation, target-shooting, sailing, caving, juggling, skiing, skating (ice and roller). Hackers' delight in techno-toys also tends to draw them towards hobbies with nifty complicated equipment that they can tinker with.

Education:

Nearly all hackers past their teens are either college-degreed or self-educated to an equivalent level. The self-taught hacker is often considered (at least by other hackers) to be better-motivated, and may be more respected, than his school-shaped counterpart. Academic areas from which people often gravitate into hackerdom include (besides the obvious computer science and electrical engineering) physics, mathematics, linguistics, and philosophy.

Things Hackers Detest and Avoid:

IBM mainframes. Smurfs, Ewoks, and other forms of offensive cuteness. Bureaucracies. Stupid people. Easy listening music. Television (except for cartoons, movies, and "Star Trek" classic). Business suits. Dishonesty. Incompetence. Boredom. COBOL. BASIC. Character-based menu interfaces.

Food:

Ethnic. Spicy. Oriental, esp. Chinese and most esp. Szechuan, Hunan, and Mandarin (hackers consider Cantonese vaguely d'eclass'e). Hackers prefer the exotic; for example, the Japanese-food fans among them will eat with gusto such delicacies as fugu (poisonous pufferfish) and whale. Thai food has experienced flurries of popularity. Where available, high-quality Jewish delicatessen food is much esteemed. A visible minority of Southwestern and Pacific Coast hackers prefers Mexican.

For those all-night hacks, pizza and microwaved burritos are big. Interestingly, though the mainstream culture has tended to think of hackers as incorrigible junk-food junkies, many have at least mildly health-foodist attitudes and are fairly discriminating about what they eat. This may be generational; anecdotal evidence suggests that the stereotype was more on the mark before the early 1980s.

Politics:

Vaguely liberal-moderate, except for the strong libertarian contingent which rejects conventional left-right politics entirely. The only safe generalization is that hackers tend to be rather anti-authoritarian; thus, both conventional conservatism and `hard' leftism are rare. Hackers are far more likely than most non-hackers to either (a) be aggressively apolitical or (b) entertain peculiar or idiosyncratic political ideas and actually try to live by them day-to-day.

Gender and Ethnicity:

Hackerdom is still predominantly male. However, the percentage of women is clearly higher than the low-single-digit range typical for technical professions, and female hackers are generally respected and dealt with as equals.

In the U.S., hackerdom is predominantly Caucasian with strong minorities of Jews (East Coast) and Orientals (West Coast). The Jewish contingent has exerted a particularly pervasive cultural influence (see {Food}, above, and note that several common jargon terms are obviously mutated Yiddish).

The ethnic distribution of hackers is understood by them to be a function of which ethnic groups tend to seek and value education. Racial and ethnic prejudice is notably uncommon and tends to be met with freezing contempt.

When asked, hackers often ascribe their culture's gender- and color-blindness to a positive effect of text-only network channels, and this is doubtless a powerful influence. Also, the ties many hackers have to AI research and SF literature may have helped them to develop an idea of personhood that is inclusive rather than exclusive --- after all, if one's imagination readily grants full human rights to future AI programs, robots, dolphins, and extraterrestrial aliens, mere color and gender can't seem very important any more.

Religion:

Agnostic. Atheist. Non-observant Jewish. Neo-pagan. Very commonly, three or more of these are combined in the same person. Conventional faith-holding Christianity is rare though not unknown.

Even hackers who identify with a religious affiliation tend to be relaxed about it, hostile to organized religion in general and all forms of religious bigotry in particular. Many enjoy `parody' religions such as Discordianism and the Church of the SubGenius.

Also, many hackers are influenced to varying degrees by Zen Buddhism or (less commonly) Taoism, and blend them easily with their `native' religions.

There is a definite strain of mystical, almost Gnostic sensibility that shows up even among those hackers not actively involved with neo-paganism, Discordianism, or Zen. Hacker folklore that pays homage to `wizards' and speaks of incantations and demons has too much psychological truthfulness about it to be entirely a joke.

Ceremonial Chemicals:

Most hackers don't smoke tobacco, and use alcohol in moderation if at all (though there is a visible contingent of exotic-beer fanciers, and a few hackers are serious oenophiles). Limited use of non-addictive psychedelic drugs, such as cannabis, LSD, psilocybin, and nitrous oxide, etc., used to be relatively common and is still regarded with more tolerance than in the mainstream culture. Use of `downers' and opiates, on the other hand, appears to be particularly rare; hackers seem in general to dislike drugs that make them stupid. On the third hand, many hackers regularly wire up on caffeine and/or sugar for all-night hacking runs.

Communication Style:

See the discussions of speech and writing styles near the beginning of this File. Though hackers often have poor person-to-person communication skills, they are as a rule quite sensitive to nuances of language and very precise in their use of it. They are often better at writing than at speaking.

Geographical Distribution:

In the United States, hackerdom revolves on a Bay Area-to-Boston axis; about half of the hard core seems to live within a hundred miles of Cambridge (Massachusetts) or Berkeley (California), although there are significant contingents in Los Angeles, in the Pacific Northwest, and around Washington DC. Hackers tend to cluster around large cities, especially `university towns' such as the Raleigh-Durham area in North Carolina or Princeton, New Jersey (this may simply reflect the fact that many are students or ex-students living near their alma maters).

Sexual Habits:

Hackerdom easily tolerates a much wider range of sexual and lifestyle variation than the mainstream culture. It includes a relatively large gay and bisexual contingent. Hackers are somewhat more likely to live in polygynous or polyandrous relationships, practice open marriage, or live in communes or group houses. In this, as in general appearance, hackerdom semi-consciously maintains `counterculture' values.

Personality Characteristics:

The most obvious common `personality' characteristics of hackers are high intelligence, consuming curiosity, and facility with intellectual abstractions. Also, most hackers are `neophiles', stimulated by and appreciative of novelty (especially intellectual novelty). Most are also relatively individualistic and anti-conformist.

Although high general intelligence is common among hackers, it is not the sine qua non one might expect. Another trait is probably even more important: the ability to mentally absorb, retain, and reference large amounts of `meaningless' detail, trusting to later experience to give it context and meaning. A person of merely average analytical intelligence who has this trait can become an effective hacker, but a creative genius who lacks it will swiftly find himself outdistanced by people who routinely upload the contents of thick reference manuals into their brains. [During the production of the first book version of this document, for example, I learned most of the rather complex typesetting language TeX over about four working days, mainly by inhaling Knuth's 477-page manual. My editor's flabbergasted reaction to this genuinely surprised me, because years of associating with hackers have conditioned me to consider such performances routine and to be expected. --ESR]

Contrary to stereotype, hackers are *not* usually intellectually narrow; they tend to be interested in any subject that can provide mental stimulation, and can often discourse knowledgeably and even interestingly on any number of obscure subjects -- if you can get them to talk at all, as opposed to, say, going back to their hacking.

It is noticeable (and contrary to many outsiders' expectations) that the better a hacker is at hacking, the more likely he or she is to have outside interests at which he or she is more than merely competent.

Hackers are `control freaks' in a way that has nothing to do with the usual coercive or authoritarian connotations of the term. In the same way that children delight in making model trains go forward and back by moving a switch, hackers love making complicated things like computers do nifty stuff for them. But it has to be *their* nifty stuff. They don't like tedium, nondeterminism, or most of the fussy, boring, ill-defined little tasks that go with maintaining a normal existence. Accordingly, they tend to be careful and orderly in their intellectual lives and chaotic elsewhere. Their code will be beautiful, even if their desks are buried in 3 feet of crap.

Hackers are generally only very weakly motivated by conventional rewards such as social approval or money. They tend to be attracted by challenges and excited by interesting toys, and to judge the interest of work or other activities in terms of the challenges offered and the toys they get to play with.

In terms of Myers-Briggs and equivalent psychometric systems, hackerdom appears to concentrate the relatively rare INTJ and INTP types; that is, introverted, intuitive, and thinker types (as opposed to the extroverted-sensate personalities that predominate in the mainstream culture). ENT[JP] types are also concentrated among hackers but are in a minority.

Weaknesses of the Hacker Personality:

Hackers have relatively little ability to identify emotionally with other people. This may be because hackers generally aren't much like `other people'. Unsurprisingly, hackers also tend towards self-absorption, intellectual arrogance, and impatience with people and tasks perceived to be wasting their time.

As cynical as hackers sometimes wax about the amount of idiocy in the world, they tend by reflex to assume that everyone is as rational, `cool', and imaginative as they consider themselves. This bias often contributes to weakness in communication skills. Hackers tend to be especially poor at confrontation and negotiation.

Because of their passionate embrace of (what they consider to be) the {Right Thing}, hackers can be unfortunately intolerant and bigoted on technical issues, in marked contrast to their general spirit of camaraderie and tolerance of alternative viewpoints otherwise. Old-time {{ITS}} partisans look down on the ever-growing hordes of {{Unix}} hackers; Unix aficionados despise {VMS} and {{MS-DOS}}; and hackers who are used to conventional command-line user interfaces loudly loathe mouse-and-menu based systems such as the Macintosh. Hackers who don't indulge in {Usenet} consider it a huge waste of time and {bandwidth}; fans of old adventure games such as {ADVENT} and {Zork} consider {MUD}s to be glorified chat systems devoid of atmosphere or interesting puzzles; hackers who are willing to devote endless hours to Usenet or MUDs consider {IRC} to be a *real* waste of time; IRCies think MUDs might be okay if there weren't all those silly puzzles in the way. And, of course, there are the perennial {holy wars} -- {EMACS} vs. {vi}, {big-endian} vs. {little-endian}, RISC vs. CISC, etc., etc., etc. As in society at large, the intensity and duration of these debates is usually inversely proportional to the number of objective, factual arguments available to buttress any position.

As a result of all the above traits, many hackers have difficulty maintaining stable relationships. At worst, they can produce the classic {computer geek}: withdrawn, relationally incompetent, sexually frustrated, and desperately unhappy when not submerged in his or her craft. Fortunately, this extreme is far less common than mainstream folklore paints it -- but almost all hackers will recognize something of themselves in the unflattering paragraphs above.

Hackers are often monumentally disorganized and sloppy about dealing with the physical world. Bills don't get paid on time, clutter piles up to incredible heights in homes and offices, and minor maintenance tasks get deferred indefinitely.

1994-95's fad behavioral disease was a syndrome called Attention Deficit Disorder, supposedly characterized by (among other things) a combination of short attention span with an ability to `hyperfocus' imaginatively on interesting tasks. There are grounds for questioning whether ADD actually exists, and if it does whether it is really a `disease' rather than an extreme of a normal genetic variation like having freckles or being able to taste DPT; but it is certainly true that many hacker traits coincide with major indicators for ADD, and probably true that ADD boosters would find a far higher rate of clinical ADD among hackers than the supposedly mainstream-normal 10%.

The sort of person who routinely uses phrases like `incompletely socialized' usually thinks hackers are. Hackers regard such people with contempt when they notice them at all.

Miscellaneous:

Hackers are more likely to have cats than dogs (in fact, it is widely grokked that cats have the hacker nature). Many drive incredibly decrepit heaps and forget to wash them; richer ones drive spiffy Porsches and RX-7s and then forget to have them washed. Almost all hackers have terribly bad handwriting, and often fall into the habit of block-printing everything like junior draftsmen.

:Helping Hacker Culture Grow: ***************************** If you enjoyed the Jargon File, please help the culture that created it grow and flourish. Here are several ways you can help:

* If you are a writer or journalist, don't say or write {hacker} when you mean {cracker}. If you work with writers or journalists, educate them on this issue and push them to do the right thing. If you catch a newspaper or magazine abusing the work `hacker', write them and straigten them out (this appendix includes a model letter).

* If you're a techie or computer hobbyist, get involved with one of the free Unixes. Toss out that lame Microsoft OS, or confine it to one disk partition and put Linux or FreeBSD or NetBSD on the other one. And the next time your friend or boss is thinking about some commercial software `solution' that costs more than it's worth, be ready to blow the competition away with free software running over a free Unix.

* Contribute to organizations like the Free Software Foundation that promote the production of high-quality free software. You can reach the Free Software Foundation at gnu@prep.ai.mit.edu, by phone at +1-617-542-5942, or by snail-mail at 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

* Support the League for Programming Freedom, which opposes over-broad software patents that constantly threaten to blow up in hackers' faces, preventing them from developing innovative software for tomorrow's needs. You can reach the League for Programming Freedom at lpf@uunet.uu.net. by phone at +1 617 621 7084, or by snail-mail at 1 Kendall Square #143, P.O.Box 9171, Cambridge, Massachusetts 02139 USA.

* If you do nothing else, please help fight government attempts to seize political control of Internet content and restrict strong cryptography. As TNHD III went to press, the so-called `Communications Decency Act' had just been declared "unconstitutional on its face" by a Federal court, but the government is expected to appeal. If it's still law when you read this, please join the effort by the Citizens' Internet Empowerment Coalition lawsuit to have the CDA quashed or repealed. Surf to the Center for Democracy and technology's home page at http://www.cdt.org to see what you can do to help fight censorship of the net.

Here's the text of a letter RMS wrote to the Wall Street Journal to complain about their policy of using "hacker" only in a pejorative sense. We hear that most major newspapers have the same policy. If you'd like to help change this situation, send your favorite newspaper the same letter -- or, better yet, write your own letter.

Dear Editor:

This letter is not meant for publication, although you can publish it if you wish. It is meant specifically for you, the editor, not the public.

I am a hacker. That is to say, I enjoy playing with computers -- working with, learning about, and writing clever computer programs. I am not a cracker; I don't make a practice of breaking computer security.

There's nothing shameful about the hacking I do. But when I tell people I am a hacker, people think I'm admitting something naughty -- because newspapers such as yours misuse the word "hacker", giving the impression that it means "security breaker" and nothing else. You are giving hackers a bad name.

The saddest thing is that this problem is perpetuated deliberately. Your reporters know the difference between "hacker" and "security breaker". They know how to make the distinction, but you don't let them! You insist on using "hacker" pejoratively. When reporters try to use another word, you change it. When reporters try to explain the other meanings, you cut it.

Of course, you have a reason. You say that readers have become used to your insulting usage of "hacker", so that you cannot change it now. Well, you can't undo past mistakes today; but that is no excuse to repeat them tomorrow.

If I were what you call a "hacker", at this point I would threaten to crack your computer and crash it. But I am a hacker, not a cracker. I don't do that kind of thing! I have enough computers to play with at home and at work; I don't need yours. Besides, it's not my way to respond to insults with violence. My response is this letter.

You owe hackers an apology; but more than that, you owe us ordinary respect.

Sincerely, etc.

:Bibliography: **************

Here are some other books you can read to help you understand the hacker mindset.

:G"odel, Escher, Bach: An Eternal Golden Braid: Douglas Hofstadter Basic Books, 1979 ISBN 0-394-74502-7

This book reads like an intellectual Grand Tour of hacker preoccupations. Music, mathematical logic, programming, speculations on the nature of intelligence, biology, and Zen are woven into a brilliant tapestry themed on the concept of encoded self-reference. The perfect left-brain companion to "Illuminatus".

:Illuminatus!: I. "The Eye in the Pyramid" II. "The Golden Apple" III. "Leviathan". Robert Shea and Robert Anton Wilson Dell, 1988 ISBN 0-440-53981-1

This work of alleged fiction is an incredible berserko-surrealist rollercoaster of world-girdling conspiracies, intelligent dolphins, the fall of Atlantis, who really killed JFK, sex, drugs, rock'n'roll, and the Cosmic Giggle Factor. First published in three volumes, but there is now a one-volume trade paperback, carried by most chain bookstores under SF. The perfect right-brain companion to Hofstadter's "G"odel, Escher, Bach". See {Eris}, {Discordianism}, {random numbers}, {Church of the SubGenius}.

:The Hitchhiker's Guide to the Galaxy: Douglas Adams Pocket Books, 1981 ISBN 0-671-46149-4

This `Monty Python in Space' spoof of SF genre traditions has been popular among hackers ever since the original British radio show. Read it if only to learn about Vogons (see {bogon}) and the significance of the number 42 (see {random numbers}) -- and why the winningest chess program of 1990 was called `Deep Thought'.

:The Tao of Programming: James Geoffrey Infobooks, 1987 ISBN 0-931137-07-1

This gentle, funny spoof of the "Tao Te Ching" contains much that is illuminating about the hacker way of thought. "When you have learned to snatch the error code from the trap frame, it will be time for you to leave."

:Hackers: Steven Levy Anchor/Doubleday 1984 ISBN 0-385-19195-2

Levy's book is at its best in describing the early MIT hackers at the Model Railroad Club and the early days of the microcomputer revolution. He never understood Unix or the networks, though, and his enshrinement of Richard Stallman as "the last true hacker" turns out (thankfully) to have been quite misleading. Numerous minor factual errors also mar the text; for example, Levy's claim that the original Jargon File derived from the TMRC Dictionary (the File originated at Stanford and was brought to MIT in 1976; the co-authors of the first edition had never seen the dictionary in question). There are also numerous misspellings in the book that inflame the passions of old-timers; as Dan Murphy, the author of TECO, once said: "You would have thought he'd take the trouble to spell the name of a winning editor right." Nevertheless, this remains a useful and stimulating book that captures the feel of several important hackish subcultures.

:The Computer Contradictionary: Stan Kelly-Bootle MIT Press, 1995 ISBN 0-262-61112-0

This pastiche of Ambrose Bierce's famous work is similar in format to the Jargon File (and quotes several entries from TNHD-2) but somewhat different in tone and intent. It is more satirical and less anthropological, and is largely a product of the author's literate and quirky imagination. For example, it defines `computer science' as "a study akin to numerology and astrology, but lacking the precision of the former and the success of the latter" and `implementation' as "The fruitless struggle by the talented and underpaid to fulfill promises made by the rich and ignorant"; `flowchart' becomes "to obfuscate a problem with esoteric cartoons". Revised and expanded from "The Devil's DP Dictionary", McGraw-Hill 1981, ISBN 0-07-034022-6.

:The Devouring Fungus: Tales from the Computer Age: Karla Jennings Norton, 1990 ISBN 0-393-30732-8

The author of this pioneering compendium knits together a great deal of computer- and hacker-related folklore with good writing and a few well-chosen cartoons. She has a keen eye for the human aspects of the lore and is very good at illuminating the psychology and evolution of hackerdom. Unfortunately, a number of small errors and awkwardnesses suggest that she didn't have the final manuscript checked over by a native speaker; the glossary in the back is particularly embarrassing, and at least one classic tale (the Magic Switch story, retold here under {A Story About `Magic'} in Appendix A is given in incomplete and badly mangled form. Nevertheless, this book is a win overall and can be enjoyed by hacker and non-hacker alike.

:The Soul of a New Machine: Tracy Kidder Little, Brown, 1981 (paperback: Avon, 1982 ISBN 0-380-59931-7)

This book (a 1982 Pulitzer Prize winner) documents the adventure of the design of a new Data General computer, the MV-8000 Eagle. It is an amazingly well-done portrait of the hacker mindset -- although largely the hardware hacker -- done by a complete outsider. It is a bit thin in spots, but with enough technical information to be entertaining to the serious hacker while providing non-technical people a view of what day-to-day life can be like -- the fun, the excitement, the disasters. During one period, when the microcode and logic were glitching at the nanosecond level, one of the overworked engineers departed the company, leaving behind a note on his terminal as his letter of resignation: "I am going to a commune in Vermont and will deal with no unit of time shorter than a season."

:Life with UNIX: a Guide for Everyone: Don Libes and Sandy Ressler Prentice-Hall, 1989 ISBN 0-13-536657-7

The authors of this book set out to tell you all the things about Unix that tutorials and technical books won't. The result is gossipy, funny, opinionated, downright weird in spots, and invaluable. Along the way they expose you to enough of Unix's history, folklore and humor to qualify as a first-class source for these things. Because so much of today's hackerdom is involved with Unix, this in turn illuminates many of its in-jokes and preoccupations.

:True Names ... and Other Dangers: Vernor Vinge Baen Books, 1987 ISBN 0-671-65363-6

Hacker demigod Richard Stallman used to say that the title story of this book "expresses the spirit of hacking best". Until the subject of the next entry came out, it was hard to even nominate another contender. The other stories in this collection are also fine work by an author who has since won multiple Hugos and is one of today's very best practitioners of hard SF.

:Snow Crash: Neal Stephenson Bantam, 1992 ISBN 0-553-56261-4

Stephenson's epic, comic cyberpunk novel is deeply knowing about the hacker psychology and its foibles in a way no other author of fiction has ever even approached. His imagination, his grasp of the relevant technical details, and his ability to communicate the excitement of hacking and its results are astonishing, delightful, and (so far) unsurpassed.

:Cyberpunk: Outlaws and Hackers on the Computer Frontier: Katie Hafner & John Markoff Simon & Schuster 1991 ISBN 0-671-68322-5

This book gathers narratives about the careers of three notorious crackers into a clear-eyed but sympathetic portrait of hackerdom's dark side. The principals are Kevin Mitnick, "Pengo" and "Hagbard" of the Chaos Computer Club, and Robert T. Morris (see {RTM}, sense 2) . Markoff and Hafner focus as much on their psychologies and motivations as on the details of their exploits, but don't slight the latter. The result is a balanced and fascinating account, particularly useful when read immediately before or after Cliff Stoll's {The Cuckoo's Egg}. It is especially instructive to compare RTM, a true hacker who blundered, with the sociopathic phone-freak Mitnick and the alienated, drug-addled crackers who made the Chaos Club notorious. The gulf between {wizard} and {wannabee} has seldom been made more obvious.

:Technobabble: John Barry MIT Press 1991 ISBN 0-262-02333-4

Barry's book takes a critical and humorous look at the `technobabble' of acronyms, neologisms, hyperbole, and metaphor spawned by the computer industry. Though he discusses some of the same mechanisms of jargon formation that occur in hackish, most of what he chronicles is actually suit-speak -- the obfuscatory language of press releases, marketroids, and Silicon Valley CEOs rather than the playful jargon of hackers (most of whom wouldn't be caught dead uttering the kind of pompous, passive-voiced word salad he deplores).

:The Cuckoo's Egg: Clifford Stoll Doubleday 1989 ISBN 0-385-24946-2

Clifford Stoll's absorbing tale of how he tracked Markus Hess and the Chaos Club cracking ring nicely illustrates the difference between `hacker' and `cracker'. Stoll's portrait of himself, his lady Martha, and his friends at Berkeley and on the Internet paints a marvelously vivid picture of how hackers and the people around them like to live and how they think.

#===================== THE JARGON FILE ENDS HERE ====================#

and here is the preface, in it's entirety, which usually precedes the document itself. Project Gutenberg readers have so often requested a document actually start at the beginning, that we do this regularly.

#======= THIS IS THE JARGON FILE, VERSION 4.0.0, 24 JUL 1996 =======#

This is the Jargon File, a comprehensive compendium of hacker slang illuminating many aspects of hackish tradition, folklore, and humor.

This document (the Jargon File) is in the public domain, to be freely used, shared, and modified. There are (by intention) no legal restraints on what you can do with it, but there are traditions about its proper use to which many hackers are quite strongly attached. Please extend the courtesy of proper citation when you quote the File, ideally with a version number, as it will change and grow over time. (Examples of appropriate citation form: "Jargon File 4.0.0" or "The on-line hacker Jargon File, version 4.0.0, 24 JUL 1996".)

The Jargon File is a common heritage of the hacker culture. Over the years a number of individuals have volunteered considerable time to maintaining the File and been recognized by the net at large as editors of it. Editorial responsibilities include: to collate contributions and suggestions from others; to seek out corroborating information; to cross-reference related entries; to keep the file in a consistent format; and to announce and distribute updated versions periodically. Current volunteer editors include:

Eric Raymond esr@snark.thyrsus.com

Although there is no requirement that you do so, it is considered good form to check with an editor before quoting the File in a published work or commercial product. We may have additional information that would be helpful to you and can assist you in framing your quote to reflect not only the letter of the File but its spirit as well.

All contributions and suggestions about this file sent to a volunteer editor are gratefully received and will be regarded, unless otherwise labelled, as freely given donations for possible use as part of this public-domain file.

From time to time a snapshot of this file has been polished, edited, and formatted for commercial publication with the cooperation of the volunteer editors and the hacker community at large. If you wish to have a bound paper copy of this file, you may find it convenient to purchase one of these. They often contain additional material not found in on-line versions. The two `authorized' editions so far are described in the Revision History section; there may be more in the future.

:Introduction: **************

This document is a collection of slang terms used by various subcultures of computer hackers. Though some technical material is included for background and flavor, it is not a technical dictionary; what we describe here is the language hackers use among themselves for fun, social communication, and technical debate.

The `hacker culture' is actually a loosely networked collection of subcultures that is nevertheless conscious of some important shared experiences, shared roots, and shared values. It has its own myths, heroes, villains, folk epics, in-jokes, taboos, and dreams. Because hackers as a group are particularly creative people who define themselves partly by rejection of `normal' values and working habits, it has unusually rich and conscious traditions for an intentional culture less than 40 years old.

As usual with slang, the special vocabulary of hackers helps hold their culture together -- it helps hackers recognize each other's places in the community and expresses shared values and experiences. Also as usual, *not* knowing the slang (or using it inappropriately) defines one as an outsider, a mundane, or (worst of all in hackish vocabulary) possibly even a {suit}. All human cultures use slang in this threefold way -- as a tool of communication, and of inclusion, and of exclusion.

Among hackers, though, slang has a subtler aspect, paralleled perhaps in the slang of jazz musicians and some kinds of fine artists but hard to detect in most technical or scientific cultures; parts of it are code for shared states of *consciousness*. There is a whole range of altered states and problem-solving mental stances basic to high-level hacking which don't fit into conventional linguistic reality any better than a Coltrane solo or one of Maurits Escher's `trompe l'oeil' compositions (Escher is a favorite of hackers), and hacker slang encodes these subtleties in many unobvious ways. As a simple example, take the distinction between a {kluge} and an {elegant} solution, and the differing connotations attached to each. The distinction is not only of engineering significance; it reaches right back into the nature of the generative processes in program design and asserts something important about two different kinds of relationship between the hacker and the hack. Hacker slang is unusually rich in implications of this kind, of overtones and undertones that illuminate the hackish psyche.

But there is more. Hackers, as a rule, love wordplay and are very conscious and inventive in their use of language. These traits seem to be common in young children, but the conformity-enforcing machine we are pleased to call an educational system bludgeons them out of most of us before adolescence. Thus, linguistic invention in most subcultures of the modern West is a halting and largely unconscious process. Hackers, by contrast, regard slang formation and use as a game to be played for conscious pleasure. Their inventions thus display an almost unique combination of the neotenous enjoyment of language-play with the discrimination of educated and powerful intelligence. Further, the electronic media which knit them together are fluid, `hot' connections, well adapted to both the dissemination of new slang and the ruthless culling of weak and superannuated specimens. The results of this process give us perhaps a uniquely intense and accelerated view of linguistic evolution in action.

Hacker slang also challenges some common linguistic and anthropological assumptions. For example, it has recently become fashionable to speak of `low-context' versus `high-context' communication, and to classify cultures by the preferred context level of their languages and art forms. It is usually claimed that low-context communication (characterized by precision, clarity, and completeness of self-contained utterances) is typical in cultures which value logic, objectivity, individualism, and competition; by contrast, high-context communication (elliptical, emotive, nuance-filled, multi-modal, heavily coded) is associated with cultures which value subjectivity, consensus, cooperation, and tradition. What then are we to make of hackerdom, which is themed around extremely low-context interaction with computers and exhibits primarily "low-context" values, but cultivates an almost absurdly high-context slang style?

The intensity and consciousness of hackish invention make a compilation of hacker slang a particularly effective window into the surrounding culture -- and, in fact, this one is the latest version of an evolving compilation called the `Jargon File', maintained by hackers themselves for over 15 years. This one (like its ancestors) is primarily a lexicon, but also includes topic entries which collect background or sidelight information on hacker culture that would be awkward to try to subsume under individual slang definitions.

Though the format is that of a reference volume, it is intended that the material be enjoyable to browse. Even a complete outsider should find at least a chuckle on nearly every page, and much that is amusingly thought-provoking. But it is also true that hackers use humorous wordplay to make strong, sometimes combative statements about what they feel. Some of these entries reflect the views of opposing sides in disputes that have been genuinely passionate; this is deliberate. We have not tried to moderate or pretty up these disputes; rather we have attempted to ensure that *everyone's* sacred cows get gored, impartially. Compromise is not particularly a hackish virtue, but the honest presentation of divergent viewpoints is.

The reader with minimal computer background who finds some references incomprehensibly technical can safely ignore them. We have not felt it either necessary or desirable to eliminate all such; they, too, contribute flavor, and one of this document's major intended audiences --- fledgling hackers already partway inside the culture -- will benefit from them.

A selection of longer items of hacker folklore and humor is included in Appendix A, {Hacker Folklore}. The `outside' reader's attention is particularly directed to Appendix B, {A Portrait of J. Random Hacker}. Appendix C, the {Bibliography}, lists some non-technical works which have either influenced or described the hacker culture.

Because hackerdom is an intentional culture (one each individual must choose by action to join), one should not be surprised that the line between description and influence can become more than a little blurred. Earlier versions of the Jargon File have played a central role in spreading hacker language and the culture that goes with it to successively larger populations, and we hope and expect that this one will do likewise.

Of Slang, Jargon, and Techspeak:

Linguists usually refer to informal language as `slang' and reserve the term `jargon' for the technical vocabularies of various occupations. However, the ancestor of this collection was called the `Jargon File', and hacker slang is traditionally `the jargon'. When talking about the jargon there is therefore no convenient way to distinguish it from what a *linguist* would call hackers' jargon --- the formal vocabulary they learn from textbooks, technical papers, and manuals.

To make a confused situation worse, the line between hacker slang and the vocabulary of technical programming and computer science is fuzzy, and shifts over time. Further, this vocabulary is shared with a wider technical culture of programmers, many of whom are not hackers and do not speak or recognize hackish slang.

Accordingly, this lexicon will try to be as precise as the facts of usage permit about the distinctions among three categories:

* `slang': informal language from mainstream English or non-technical subcultures (bikers, rock fans, surfers, etc).

* `jargon': without qualifier, denotes informal `slangy' language peculiar to or predominantly found among hackers -- the subject of this lexicon.

* `techspeak': the formal technical vocabulary of programming, computer science, electronics, and other fields connected to hacking.

This terminology will be consistently used throughout the remainder of this lexicon.

The jargon/techspeak distinction is the delicate one. A lot of techspeak originated as jargon, and there is a steady continuing uptake of jargon into techspeak. On the other hand, a lot of jargon arises from overgeneralization of techspeak terms (there is more about this in the {Jargon Construction} section below).

In general, we have considered techspeak any term that communicates primarily by a denotation well established in textbooks, technical dictionaries, or standards documents.

A few obviously techspeak terms (names of operating systems, languages, or documents) are listed when they are tied to hacker folklore that isn't covered in formal sources, or sometimes to convey critical historical background necessary to understand other entries to which they are cross-referenced. Some other techspeak senses of jargon words are listed in order to make the jargon senses clear; where the text does not specify that a straight technical sense is under discussion, these are marked with `[techspeak]' as an etymology. Some entries have a primary sense marked this way, with subsequent jargon meanings explained in terms of it.

We have also tried to indicate (where known) the apparent origins of terms. The results are probably the least reliable information in the lexicon, for several reasons. For one thing, it is well known that many hackish usages have been independently reinvented multiple times, even among the more obscure and intricate neologisms. It often seems that the generative processes underlying hackish jargon formation have an internal logic so powerful as to create substantial parallelism across separate cultures and even in different languages! For another, the networks tend to propagate innovations so quickly that `first use' is often impossible to pin down. And, finally, compendia like this one alter what they observe by implicitly stamping cultural approval on terms and widening their use.

Despite these problems, the organized collection of jargon-related oral history for the new compilations has enabled us to put to rest quite a number of folk etymologies, place credit where credit is due, and illuminate the early history of many important hackerisms such as {kluge}, {cruft}, and {foo}. We believe specialist lexicographers will find many of the historical notes more than casually instructive.

Revision History:

The original Jargon File was a collection of hacker jargon from technical cultures including the MIT AI Lab, the Stanford AI lab (SAIL), and others of the old ARPANET AI/LISP/PDP-10 communities including Bolt, Beranek and Newman (BBN), Carnegie-Mellon University (CMU), and Worcester Polytechnic Institute (WPI).

The Jargon File (hereafter referred to as `jargon-1' or `the File') was begun by Raphael Finkel at Stanford in 1975. From this time until the plug was finally pulled on the SAIL computer in 1991, the File was named AIWORD.RF[UP,DOC] there. Some terms in it date back considerably earlier ({frob} and some senses of {moby}, for instance, go back to the Tech Model Railroad Club at MIT and are believed to date at least back to the early 1960s). The revisions of jargon-1 were all unnumbered and may be collectively considered `Version 1'.

In 1976, Mark Crispin, having seen an announcement about the File on the SAIL computer, {FTP}ed a copy of the File to MIT. He noticed that it was hardly restricted to `AI words' and so stored the file on his directory as AI:MRC;SAIL JARGON.

The file was quickly renamed JARGON > (the `>' caused versioning under ITS) as a flurry of enhancements were made by Mark Crispin and Guy L. Steele Jr. Unfortunately, amidst all this activity, nobody thought of correcting the term `jargon' to `slang' until the compendium had already become widely known as the Jargon File.

Raphael Finkel dropped out of active participation shortly thereafter and Don Woods became the SAIL contact for the File (which was subsequently kept in duplicate at SAIL and MIT, with periodic resynchronizations).

The File expanded by fits and starts until about 1983; Richard Stallman was prominent among the contributors, adding many MIT and ITS-related coinages.

In Spring 1981, a hacker named Charles Spurgeon got a large chunk of the File published in Stewart Brand's "CoEvolution Quarterly" (issue 29, pages 26--35) with illustrations by Phil Wadler and Guy Steele (including a couple of the Crunchly cartoons). This appears to have been the File's first paper publication.

A late version of jargon-1, expanded with commentary for the mass market, was edited by Guy Steele into a book published in 1983 as "The Hacker's Dictionary" (Harper & Row CN 1082, ISBN 0-06-091082-8). The other jargon-1 editors (Raphael Finkel, Don Woods, and Mark Crispin) contributed to this revision, as did Richard M. Stallman and Geoff Goodfellow. This book (now out of print) is hereafter referred to as `Steele-1983' and those six as the Steele-1983 coauthors.

Shortly after the publication of Steele-1983, the File effectively stopped growing and changing. Originally, this was due to a desire to freeze the file temporarily to facilitate the production of Steele-1983, but external conditions caused the `temporary' freeze to become permanent.

The AI Lab culture had been hit hard in the late 1970s by funding cuts and the resulting administrative decision to use vendor-supported hardware and software instead of homebrew whenever possible. At MIT, most AI work had turned to dedicated LISP Machines. At the same time, the commercialization of AI technology lured some of the AI Lab's best and brightest away to startups along the Route 128 strip in Massachusetts and out West in Silicon Valley. The startups built LISP machines for MIT; the central MIT-AI computer became a {TWENEX} system rather than a host for the AI hackers' beloved {ITS}.

The Stanford AI Lab had effectively ceased to exist by 1980, although the SAIL computer continued as a Computer Science Department resource until 1991. Stanford became a major {TWENEX} site, at one point operating more than a dozen TOPS-20 systems; but by the mid-1980s most of the interesting software work was being done on the emerging BSD Unix standard.

In April 1983, the PDP-10-centered cultures that had nourished the File were dealt a death-blow by the cancellation of the Jupiter project at Digital Equipment Corporation. The File's compilers, already dispersed, moved on to other things. Steele-1983 was partly a monument to what its authors thought was a dying tradition; no one involved realized at the time just how wide its influence was to be.

By the mid-1980s the File's content was dated, but the legend that had grown up around it never quite died out. The book, and softcopies obtained off the ARPANET, circulated even in cultures far removed from MIT and Stanford; the content exerted a strong and continuing influence on hacker language and humor. Even as the advent of the microcomputer and other trends fueled a tremendous expansion of hackerdom, the File (and related materials such as the {AI Koans} in Appendix A) came to be seen as a sort of sacred epic, a hacker-culture Matter of Britain chronicling the heroic exploits of the Knights of the Lab. The pace of change in hackerdom at large accelerated tremendously -- but the Jargon File, having passed from living document to icon, remained essentially untouched for seven years.

This revision contains nearly the entire text of a late version of jargon-1 (a few obsolete PDP-10-related entries were dropped after careful consultation with the editors of Steele-1983). It merges in about 80% of the Steele-1983 text, omitting some framing material and a very few entries introduced in Steele-1983 that are now also obsolete.

This new version casts a wider net than the old Jargon File; its aim is to cover not just AI or PDP-10 hacker culture but all the technical computing cultures wherein the true hacker-nature is manifested. More than half of the entries now derive from {Usenet} and represent jargon now current in the C and Unix communities, but special efforts have been made to collect jargon from other cultures including IBM PC programmers, Amiga fans, Mac enthusiasts, and even the IBM mainframe world.

Eric S. Raymond maintains the new File with assistance from Guy L. Steele Jr. ; these are the persons primarily reflected in the File's editorial `we', though we take pleasure in acknowledging the special contribution of the other coauthors of Steele-1983. Please email all additions, corrections, and correspondence relating to the Jargon File to jargon@thyrsus.com.

(Warning: other email addresses appear in this file *but are not guaranteed to be correct* later than the revision date on the first line. *Don't* email us if an attempt to reach your idol bounces --- we have no magic way of checking addresses or looking up people.)

The 2.9.6 version became the main text of "The New Hacker's Dictionary", by Eric Raymond (ed.), MIT Press 1991, ISBN 0-262-68069-6.

The 3.0.0 version was published in September 1993 as the second edition of "The New Hacker's Dictionary", again from MIT Press (ISBN 0-262-18154-1).

If you want the book, you should be able to find it at any of the major bookstore chains. Failing that, you can order by mail from

The MIT Press 55 Hayward Street Cambridge, MA 02142

or order by phone at (800)-356-0343 or (617)-625-8481.

The maintainers are committed to updating the on-line version of the Jargon File through and beyond paper publication, and will continue to make it available to archives and public-access sites as a trust of the hacker community.

Here is a chronology of the high points in the recent on-line revisions:

Version 2.1.1, Jun 12 1990: the Jargon File comes alive again after a seven-year hiatus. Reorganization and massive additions were by Eric S. Raymond, approved by Guy Steele. Many items of UNIX, C, USENET, and microcomputer-based jargon were added at that time.

Version 2.9.6, Aug 16 1991: corresponds to reproduction copy for book. This version had 18952 lines, 148629 words, 975551 characters, and 1702 entries.

Version 2.9.8, Jan 01 1992: first public release since the book, including over fifty new entries and numerous corrections/additions to old ones. Packaged with version 1.1 of vh(1) hypertext reader. This version had 19509 lines, 153108 words, 1006023 characters, and 1760 entries.

Version 2.9.9, Apr 01 1992: folded in XEROX PARC lexicon. This version had 20298 lines, 159651 words, 1048909 characters, and 1821 entries.

Version 2.9.10, Jul 01 1992: lots of new historical material. This version had 21349 lines, 168330 words, 1106991 characters, and 1891 entries.

Version 2.9.11, Jan 01 1993: lots of new historical material. This version had 21725 lines, 171169 words, 1125880 characters, and 1922 entries.

Version 2.9.12, May 10 1993: a few new entries & changes, marginal MUD/IRC slang and some borderline techspeak removed, all in preparation for 2nd Edition of TNHD. This version had 22238 lines, 175114 words, 1152467 characters, and 1946 entries.

Version 3.0.0, Jul 27 1993: manuscript freeze for 2nd edition of TNHD. This version had 22548 lines, 177520 words, 1169372 characters, and 1961 entries.

Version 3.1.0, Oct 15 1994: interim release to test WWW conversion. This version had 23197 lines, 181001 words, 1193818 characters, and 1990 entries.

Version 3.2.0, Mar 15 1995: Spring 1995 update. This version had 23822 lines, 185961 words, 1226358 characters, and 2031 entries.

Version 3.3.0, Jan 20 1996: Winter 1996 update. This version had 24055 lines, 187957 words, 1239604 characters, and 2045 entries.

Version 3.3.1, Jan 25 1996: Copy-corrected improvement on 3.3.0 shipped to MIT Press as a step towards TNHD III. This version had 24147 lines, 188728 words, 1244554 characters, and 2050 entries.

Version 3.3.2, Mar 20 1996: A number of new entries pursuant on 3.3.2. This version had 24442 lines, 190867 words, 1262468 characters, and 2061 entries.

Version 3.3.3, Mar 25 1996: Cleanup before TNHD III manuscript freeze. This version had 24584 lines, 191932 words, 1269996 characters, and 2064 entries.

Version 4.0.0, Jul 25 1996: The actual TNHD III version after copy-edit. This version had 24801 lines, 193697 words, 1281402 characters, and 2067 entries.

Version numbering: Version numbers should be read as major.minor.revision. Major version 1 is reserved for the `old' (ITS) Jargon File, jargon-1. Major version 2 encompasses revisions by ESR (Eric S. Raymond) with assistance from GLS (Guy L. Steele, Jr.) leading up to and including the second paper edition. From now on, major version number N.00 will probably correspond to the Nth paper edition. Usually later versions will either completely supersede or incorporate earlier versions, so there is generally no point in keeping old versions around.

Our thanks to the coauthors of Steele-1983 for oversight and assistance, and to the hundreds of Usenetters (too many to name here) who contributed entries and encouragement. More thanks go to several of the old-timers on the Usenet group alt.folklore.computers, who contributed much useful commentary and many corrections and valuable historical perspective: Joseph M. Newcomer , Bernie Cosell , Earl Boebert , and Joe Morris .

We were fortunate enough to have the aid of some accomplished linguists. David Stampe and Charles Hoequist contributed valuable criticism; Joe Keane helped us improve the pronunciation guides.

A few bits of this text quote previous works. We are indebted to Brian A. LaMacchia for obtaining permission for us to use material from the "TMRC Dictionary"; also, Don Libes contributed some appropriate material from his excellent book "Life With UNIX". We thank Per Lindberg , author of the remarkable Swedish-language 'zine "Hackerbladet", for bringing "FOO!" comics to our attention and smuggling one of the IBM hacker underground's own baby jargon files out to us. Thanks also to Maarten Litmaath for generously allowing the inclusion of the ASCII pronunciation guide he formerly maintained. And our gratitude to Marc Weiser of XEROX PARC for securing us permission to quote from PARC's own jargon lexicon and shipping us a copy.

It is a particular pleasure to acknowledge the major contributions of Mark Brader and Steve Summit to the File and Dictionary; they have read and reread many drafts, checked facts, caught typos, submitted an amazing number of thoughtful comments, and done yeoman service in catching typos and minor usage bobbles. Their rare combination of enthusiasm, persistence, wide-ranging technical knowledge, and precisionism in matters of language has been of invaluable help. Indeed, the sustained volume and quality of Mr. Brader's input over several years and several different editions has only allowed him to escape co-editor credit by the slimmest of margins.

Finally, George V. Reilly helped with TeX arcana and painstakingly proofread some 2.7 and 2.8 versions, and Eric Tiedemann contributed sage advice throughout on rhetoric, amphigory, and philosophunculism.

:How Jargon Works: ******************

Jargon Construction:

There are some standard methods of jargonification that became established quite early (i.e., before 1970), spreading from such sources as the Tech Model Railroad Club, the PDP-1 SPACEWAR hackers, and John McCarthy's original crew of LISPers. These include verb doubling, soundalike slang, the `-P' convention, overgeneralization, spoken inarticulations, and anthropomorphization. Each is discussed below. We also cover the standard comparatives for design quality.

Of these six, verb doubling, overgeneralization, anthropomorphization, and (especially) spoken inarticulations have become quite general; but soundalike slang is still largely confined to MIT and other large universities, and the `-P' convention is found only where LISPers flourish.

:Verb Doubling: ---------------

A standard construction in English is to double a verb and use it as an exclamation, such as "Bang, bang!" or "Quack, quack!". Most of these are names for noises. Hackers also double verbs as a concise, sometimes sarcastic comment on what the implied subject does. Also, a doubled verb is often used to terminate a conversation, in the process remarking on the current state of affairs or what the speaker intends to do next. Typical examples involve {win}, {lose}, {hack}, {flame}, {barf}, {chomp}:

"The disk heads just crashed." "Lose, lose." "Mostly he talked about his latest crock. Flame, flame." "Boy, what a bagbiter! Chomp, chomp!"

Some verb-doubled constructions have special meanings not immediately obvious from the verb. These have their own listings in the lexicon.

The {Usenet} culture has one *tripling* convention unrelated to this; the names of `joke' topic groups often have a tripled last element. The first and paradigmatic example was alt.swedish.chef.bork.bork.bork (a "Muppet Show" reference); other infamous examples have included:

alt.french.captain.borg.borg.borg alt.wesley.crusher.die.die.die comp.unix.internals.system.calls.brk.brk.brk sci.physics.edward.teller.boom.boom.boom alt.sadistic.dentists.drill.drill.drill

:Soundalike slang: ------------------

Hackers will often make rhymes or puns in order to convert an ordinary word or phrase into something more interesting. It is considered particularly {flavorful} if the phrase is bent so as to include some other jargon word; thus the computer hobbyist magazine "Dr. Dobb's Journal" is almost always referred to among hackers as `Dr. Frob's Journal' or simply `Dr. Frob's'. Terms of this kind that have been in fairly wide use include names for newspapers:

Boston Herald => Horrid (or Harried) Boston Globe => Boston Glob Houston (or San Francisco) Chronicle => the Crocknicle (or the Comical) New York Times => New York Slime

However, terms like these are often made up on the spur of the moment. Standard examples include:

Data General => Dirty Genitals IBM 360 => IBM Three-Sickly Government Property -- Do Not Duplicate (on keys) => Government Duplicity -- Do Not Propagate for historical reasons => for hysterical raisins Margaret Jacks Hall (the CS building at Stanford) => Marginal Hacks Hall

This is not really similar to the Cockney rhyming slang it has been compared to in the past, because Cockney substitutions are opaque whereas hacker punning jargon is intentionally transparent.

:The `-P' convention: ---------------------

Turning a word into a question by appending the syllable `P'; from the LISP convention of appending the letter `P' to denote a predicate (a boolean-valued function). The question should expect a yes/no answer, though it needn't. (See {T} and {NIL}.)

At dinnertime: Q: "Foodp?" A: "Yeah, I'm pretty hungry." or "T!"

At any time: Q: "State-of-the-world-P?" A: (Straight) "I'm about to go home." A: (Humorous) "Yes, the world has a state."

On the phone to Florida: Q: "State-p Florida?" A: "Been reading JARGON.TXT again, eh?"

[One of the best of these is a {Gosperism}. Once, when we were at a Chinese restaurant, Bill Gosper wanted to know whether someone would like to share with him a two-person-sized bowl of soup. His inquiry was: "Split-p soup?" -- GLS]

:Overgeneralization: --------------------

A very conspicuous feature of jargon is the frequency with which techspeak items such as names of program tools, command language primitives, and even assembler opcodes are applied to contexts outside of computing wherever hackers find amusing analogies to them. Thus (to cite one of the best-known examples) Unix hackers often {grep} for things rather than searching for them. Many of the lexicon entries are generalizations of exactly this kind.

Hackers enjoy overgeneralization on the grammatical level as well. Many hackers love to take various words and add the wrong endings to them to make nouns and verbs, often by extending a standard rule to nonuniform cases (or vice versa). For example, because

porous => porosity generous => generosity

hackers happily generalize:

mysterious => mysteriosity ferrous => ferrosity obvious => obviosity dubious => dubiosity

Another class of common construction uses the suffix `-itude' to abstract a quality from just about any adjective or noun. This usage arises especially in cases where mainstream English would perform the same abstraction through `-iness' or `-ingness'. Thus:

win => winnitude (a common exclamation) loss => lossitude cruft => cruftitude lame => lameitude

Some hackers cheerfully reverse this transformation; they argue, for example, that the horizontal degree lines on a globe ought to be called `lats' -- after all, they're measuring latitude!

Also, note that all nouns can be verbed. E.g.: "All nouns can be verbed", "I'll mouse it up", "Hang on while I clipboard it over", "I'm grepping the files". English as a whole is already heading in this direction (towards pure-positional grammar like Chinese); hackers are simply a bit ahead of the curve.

However, hackers avoid the unimaginative verb-making techniques characteristic of marketroids, bean-counters, and the Pentagon; a hacker would never, for example, `productize', `prioritize', or `securitize' things. Hackers have a strong aversion to bureaucratic bafflegab and regard those who use it with contempt.

Similarly, all verbs can be nouned. This is only a slight overgeneralization in modern English; in hackish, however, it is good form to mark them in some standard nonstandard way. Thus:

win => winnitude, winnage disgust => disgustitude hack => hackification

Further, note the prevalence of certain kinds of nonstandard plural forms. Some of these go back quite a ways; the TMRC Dictionary includes an entry which implies that the plural of `mouse' is {meeces}, and notes that the defined plural of `caboose' is `cabeese'. This latter has apparently been standard (or at least a standard joke) among railfans (railroad enthusiasts) for many years.

On a similarly Anglo-Saxon note, almost anything ending in `x' may form plurals in `-xen' (see {VAXen} and {boxen} in the main text). Even words ending in phonetic /k/ alone are sometimes treated this way; e.g., `soxen' for a bunch of socks. Other funny plurals are `frobbotzim' for the plural of `frobbozz' (see {frobnitz}) and `Unices' and `Twenices' (rather than `Unixes' and `Twenexes'; see {Unix}, {TWENEX} in main text). But note that `Unixen' and `Twenexen' are never used; it has been suggested that this is because `-ix' and `-ex' are Latin singular endings that attract a Latinate plural. Finally, it has been suggested to general approval that the plural of `mongoose' ought to be `polygoose'.

The pattern here, as with other hackish grammatical quirks, is generalization of an inflectional rule that in English is either an import or a fossil (such as the Hebrew plural ending `-im', or the Anglo-Saxon plural suffix `-en') to cases where it isn't normally considered to apply.

This is not `poor grammar', as hackers are generally quite well aware of what they are doing when they distort the language. It is grammatical creativity, a form of playfulness. It is done not to impress but to amuse, and never at the expense of clarity.

:Spoken inarticulations: ------------------------

Words such as `mumble', `sigh', and `groan' are spoken in places where their referent might more naturally be used. It has been suggested that this usage derives from the impossibility of representing such noises on a comm link or in electronic mail (interestingly, the same sorts of constructions have been showing up with increasing frequency in comic strips). Another expression sometimes heard is "Complain!", meaning "I have a complaint!"

:Anthropomorphization: ----------------------

Semantically, one rich source of jargon constructions is the hackish tendency to anthropomorphize hardware and software. This isn't done in a naive way; hackers don't personalize their stuff in the sense of feeling empathy with it, nor do they mystically believe that the things they work on every day are `alive'. What *is* common is to hear hardware or software talked about as though it has homunculi talking to each other inside it, with intentions and desires. Thus, one hears "The protocol handler got confused", or that programs "are trying" to do things, or one may say of a routine that "its goal in life is to X". One even hears explanations like "... and its poor little brain couldn't understand X, and it died." Sometimes modelling things this way actually seems to make them easier to understand, perhaps because it's instinctively natural to think of anything with a really complex behavioral repertoire as `like a person' rather than `like a thing'.

:Comparatives: --------------

Finally, note that many words in hacker jargon have to be understood as members of sets of comparatives. This is especially true of the adjectives and nouns used to describe the beauty and functional quality of code. Here is an approximately correct spectrum:

monstrosity brain-damage screw bug lose misfeature crock kluge hack win feature elegance perfection

The last is spoken of as a mythical absolute, approximated but never actually attained. Another similar scale is used for describing the reliability of software:

broken flaky dodgy fragile brittle solid robust bulletproof armor-plated

Note, however, that `dodgy' is primarily Commonwealth Hackish (it is rare in the U.S.) and may change places with `flaky' for some speakers.

Coinages for describing {lossage} seem to call forth the very finest in hackish linguistic inventiveness; it has been truly said that hackers have even more words for equipment failures than Yiddish has for obnoxious people.

Hacker Writing Style:

We've already seen that hackers often coin jargon by overgeneralizing grammatical rules. This is one aspect of a more general fondness for form-versus-content language jokes that shows up particularly in hackish writing. One correspondent reports that he consistently misspells `wrong' as `worng'. Others have been known to criticize glitches in Jargon File drafts by observing (in the mode of Douglas Hofstadter) "This sentence no verb", or "Too repetetetive", or "Bad speling", or "Incorrectspa cing." Similarly, intentional spoonerisms are often made of phrases relating to confusion or things that are confusing; `dain bramage' for `brain damage' is perhaps the most common (similarly, a hacker would be likely to write "Excuse me, I'm cixelsyd today", rather than "I'm dyslexic today"). This sort of thing is quite common and is enjoyed by all concerned.

Hackers tend to use quotes as balanced delimiters like parentheses, much to the dismay of American editors. Thus, if "Jim is going" is a phrase, and so are "Bill runs" and "Spock groks", then hackers generally prefer to write: "Jim is going", "Bill runs", and "Spock groks". This is incorrect according to standard American usage (which would put the continuation commas and the final period inside the string quotes); however, it is counter-intuitive to hackers to mutilate literal strings with characters that don't belong in them. Given the sorts of examples that can come up in discussions of programming, American-style quoting can even be grossly misleading. When communicating command lines or small pieces of code, extra characters can be a real pain in the neck.

Consider, for example, a sentence in a {vi} tutorial that looks like this:

Then delete a line from the file by typing "dd".

Standard usage would make this

Then delete a line from the file by typing "dd."

but that would be very bad -- because the reader would be prone to type the string d-d-dot, and it happens that in `vi(1)' dot repeats the last command accepted. The net result would be to delete *two* lines!

The Jargon File follows hackish usage throughout.

Interestingly, a similar style is now preferred practice in Great Britain, though the older style (which became established for typographical reasons having to do with the aesthetics of comma and quotes in typeset text) is still accepted there. "Hart's Rules" and the "Oxford Dictionary for Writers and Editors" call the hacker-like style `new' or `logical' quoting.

Another hacker habit is a tendency to distinguish between `scare' quotes and `speech' quotes; that is, to use British-style single quotes for marking and reserve American-style double quotes for actual reports of speech or text included from elsewhere. Interestingly, some authorities describe this as correct general usage, but mainstream American English has gone to using double-quotes indiscriminately enough that hacker usage appears marked [and, in fact, I thought this was a personal quirk of mine until I checked with Usenet --ESR]. One further permutation that is definitely *not* standard is a hackish tendency to do marking quotes by using apostrophes (single quotes) in pairs; that is, 'like this'. This is modelled on string and character literal syntax in some programming languages (reinforced by the fact that many character-only terminals display the apostrophe in typewriter style, as a vertical single quote).

One quirk that shows up frequently in the {email} style of Unix hackers in particular is a tendency for some things that are normally all-lowercase (including usernames and the names of commands and C routines) to remain uncapitalized even when they occur at the beginning of sentences. It is clear that, for many hackers, the case of such identifiers becomes a part of their internal representation (the `spelling') and cannot be overridden without mental effort (an appropriate reflex because Unix and C both distinguish cases and confusing them can lead to {lossage}). A way of escaping this dilemma is simply to avoid using these constructions at the beginning of sentences.

There seems to be a meta-rule behind these nonstandard hackerisms to the effect that precision of expression is more important than conformance to traditional rules; where the latter create ambiguity or lose information they can be discarded without a second thought. It is notable in this respect that other hackish inventions (for example, in vocabulary) also tend to carry very precise shades of meaning even when constructed to appear slangy and loose. In fact, to a hacker, the contrast between `loose' form and `tight' content in jargon is a substantial part of its humor!

Hackers have also developed a number of punctuation and emphasis conventions adapted to single-font all-ASCII communications links, and these are occasionally carried over into written documents even when normal means of font changes, underlining, and the like are available.

One of these is that TEXT IN ALL CAPS IS INTERPRETED AS `LOUD', and this becomes such an ingrained synesthetic reflex that a person who goes to caps-lock while in {talk mode} may be asked to "stop shouting, please, you're hurting my ears!".

Also, it is common to use bracketing with unusual characters to signify emphasis. The asterisk is most common, as in "What the *hell*?" even though this interferes with the common use of the asterisk suffix as a footnote mark. The underscore is also common, suggesting underlining (this is particularly common with book titles; for example, "It is often alleged that Joe Haldeman wrote _The_Forever_War_ as a rebuttal to Robert Heinlein's earlier novel of the future military, _Starship_Troopers_."). Other forms exemplified by "=hell=", "\hell/", or "/hell/" are occasionally seen (it's claimed that in the last example the first slash pushes the letters over to the right to make them italic, and the second keeps them from falling over). Finally, words may also be emphasized L I K E T H I S, or by a series of carets (^) under them on the next line of the text.

There is a semantic difference between *emphasis like this* (which emphasizes the phrase as a whole), and *emphasis* *like* *this* (which suggests the writer speaking very slowly and distinctly, as if to a very young child or a mentally impaired person). Bracketing a word with the `*' character may also indicate that the writer wishes readers to consider that an action is taking place or that a sound is being made. Examples: *bang*, *hic*, *ring*, *grin*, *kick*, *stomp*, *mumble*.

One might also see the above sound effects as , , , , , , . This use of angle brackets to mark their contents originally derives from conventions used in {BNF}, but since about 1993 it has been reinforced by the HTML markup used on the World Wide Web.

Angle-bracket enclosure is also used to indicate that a term stands for some {random} member of a larger class (this is straight from {BNF}). Examples like the following are common:

So this walks into a bar one day...

There is also an accepted convention for `writing under erasure'; the text

Be nice to this fool^H^H^H^Hgentleman, he's visiting from corporate HQ.

reads roughly as "Be nice to this fool, er, gentleman...". This comes from the fact that the digraph ^H is often used as a print representation for a backspace. It parallels (and may have been influenced by) the ironic use of `slashouts' in science-fiction fanzines.

A related habit uses editor commands to signify corrections to previous text. This custom is fading as more mailers get good editing capabilities, but one occasionally still sees things like this:

I've seen that term used on alt.foobar often. Send it to Erik for the File. Oops...s/Erik/Eric/.

The s/Erik/Eric/ says "change Erik to Eric in the preceding". This syntax is borrowed from the Unix editing tools `ed' and `sed', but is widely recognized by non-Unix hackers as well.

In a formula, `*' signifies multiplication but two asterisks in a row are a shorthand for exponentiation (this derives from FORTRAN). Thus, one might write 2 ** 8 = 256.

Another notation for exponentiation one sees more frequently uses the caret (^, ASCII 1011110); one might write instead `2^8 = 256'. This goes all the way back to Algol-60, which used the archaic ASCII `up-arrow' that later became the caret; this was picked up by Kemeny and Kurtz's original BASIC, which in turn influenced the design of the `bc(1)' and `dc(1)' Unix tools, which have probably done most to reinforce the convention on Usenet. The notation is mildly confusing to C programmers, because `^' means bitwise exclusive-or in C. Despite this, it was favored 3:1 over ** in a late-1990 snapshot of Usenet. It is used consistently in this lexicon.

In on-line exchanges, hackers tend to use decimal forms or improper fractions (`3.5' or `7/2') rather than `typewriter style' mixed fractions (`3-1/2'). The major motive here is probably that the former are more readable in a monospaced font, together with a desire to avoid the risk that the latter might be read as `three minus one-half'. The decimal form is definitely preferred for fractions with a terminating decimal representation; there may be some cultural influence here from the high status of scientific notation.

Another on-line convention, used especially for very large or very small numbers, is taken from C (which derived it from FORTRAN). This is a form of `scientific notation' using `e' to replace `*10^'; for example, one year is about 3e7 seconds long.

The tilde (~) is commonly used in a quantifying sense of `approximately'; that is, `~50' means `about fifty'.

On Usenet and in the {MUD} world, common C boolean, logical, and relational operators such as `|', `&', `||', `&&', `!', `==', `!=', `>', `<', `>=', and `=<' are often combined with English. The Pascal not-equals, `<>', is also recognized, and occasionally one sees `/=' for not-equals (from Ada, Common Lisp, and Fortran 90). The use of prefix `!' as a loose synonym for `not-' or `no-' is particularly common; thus, `!clue' is read `no-clue' or `clueless'.

A related practice borrows syntax from preferred programming languages to express ideas in a natural-language text. For example, one might see the following:

In J. R. Hacker wrote: >I recently had occasion to field-test the Snafu >Systems 2300E adaptive gonkulator. The price was >right, and the racing stripe on the case looked >kind of neat, but its performance left something >to be desired.

Yeah, I tried one out too.

#ifdef FLAME Hasn't anyone told those idiots that you can't get decent bogon suppression with AFJ filters at today's net volumes? #endif /* FLAME */

I guess they figured the price premium for true frame-based semantic analysis was too high. Unfortunately, it's also the only workable approach. I wouldn't recommend purchase of this product unless you're on a *very* tight budget.

#include -- == Frank Foonly (Fubarco Systems)

In the above, the `#ifdef'/`#endif' pair is a conditional compilation syntax from C; here, it implies that the text between (which is a {flame}) should be evaluated only if you have turned on (or defined on) the switch FLAME. The `#include' at the end is C for "include standard disclaimer here"; the `standard disclaimer' is understood to read, roughly, "These are my personal opinions and not to be construed as the official position of my employer."

The top section in the example, with > at the left margin, is an example of an inclusion convention we'll discuss below.

More recently, following on the huge popularity of the World Wide Web, pseudo-HTML markup has become popular for similar purposes:

Your father was a hamster and your mother smelt of elderberries!

You'll even see this with an HTML-style modifier:

You seem well-suited for a career in government.

Hackers also mix letters and numbers more freely than in mainstream usage. In particular, it is good hackish style to write a digit sequence where you intend the reader to understand the text string that names that number in English. So, hackers prefer to write `1970s' rather than `nineteen-seventies' or `1970's' (the latter looks like a possessive).

It should also be noted that hackers exhibit much less reluctance to use multiply nested parentheses than is normal in English. Part of this is almost certainly due to influence from LISP (which uses deeply nested parentheses (like this (see?)) in its syntax a lot), but it has also been suggested that a more basic hacker trait of enjoying playing with complexity and pushing systems to their limits is in operation.

Finally, it is worth mentioning that many studies of on-line communication have shown that electronic links have a de-inhibiting effect on people. Deprived of the body-language cues through which emotional state is expressed, people tend to forget everything about other parties except what is presented over that ASCII link. This has both good and bad effects. A good one is that it encourages honesty and tends to break down hierarchical authority relationships; a bad one is that it may encourage depersonalization and gratuitous rudeness. Perhaps in response to this, experienced netters often display a sort of conscious formal politesse in their writing that has passed out of fashion in other spoken and written media (for example, the phrase "Well said, sir!" is not uncommon).

Many introverted hackers who are next to inarticulate in person communicate with considerable fluency over the net, perhaps precisely because they can forget on an unconscious level that they are dealing with people and thus don't feel stressed and anxious as they would face to face.

Though it is considered gauche to publicly criticize posters for poor spelling or grammar, the network places a premium on literacy and clarity of expression. It may well be that future historians of literature will see in it a revival of the great tradition of personal letters as art.

Email Quotes and Inclusion Conventions:

One area where conventions for on-line writing are still in some flux is the marking of included material from earlier messages -- what would be called `block quotations' in ordinary English. From the usual typographic convention employed for these (smaller font at an extra indent), there derived a practice of included text being indented by one ASCII TAB (0001001) character, which under Unix and many other environments gives the appearance of an 8-space indent.

Early mail and netnews readers had no facility for including messages this way, so people had to paste in copy manually. BSD `Mail(1)' was the first message agent to support inclusion, and early Usenetters emulated its style. But the TAB character tended to push included text too far to the right (especially in multiply nested inclusions), leading to ugly wraparounds. After a brief period of confusion (during which an inclusion leader consisting of three or four spaces became established in EMACS and a few mailers), the use of leading `>' or `> ' became standard, perhaps owing to its use in `ed(1)' to display tabs (alternatively, it may derive from the `>' that some early Unix mailers used to quote lines starting with "From" in text, so they wouldn't look like the beginnings of new message headers). Inclusions within inclusions keep their `>' leaders, so the `nesting level' of a quotation is visually apparent.

The practice of including text from the parent article when posting a followup helped solve what had been a major nuisance on Usenet: the fact that articles do not arrive at different sites in the same order. Careless posters used to post articles that would begin with, or even consist entirely of, "No, that's wrong" or "I agree" or the like. It was hard to see who was responding to what. Consequently, around 1984, new news-posting software evolved a facility to automatically include the text of a previous article, marked with "> " or whatever the poster chose. The poster was expected to delete all but the relevant lines. The result has been that, now, careless posters post articles containing the *entire* text of a preceding article, *followed* only by "No, that's wrong" or "I agree".

Many people feel that this cure is worse than the original disease, and there soon appeared newsreader software designed to let the reader skip over included text if desired. Today, some posting software rejects articles containing too high a proportion of lines beginning with `>' -- but this too has led to undesirable workarounds, such as the deliberate inclusion of zero-content filler lines which aren't quoted and thus pull the message below the rejection threshold.

Because the default mailers supplied with Unix and other operating systems haven't evolved as quickly as human usage, the older conventions using a leading TAB or three or four spaces are still alive; however, >-inclusion is now clearly the prevalent form in both netnews and mail.

Inclusion practice is still evolving, and disputes over the `correct' inclusion style occasionally lead to {holy wars}.

Most netters view an inclusion as a promise that comment on it will immediately follow. The preferred, conversational style looks like this,

> relevant excerpt 1 response to excerpt > relevant excerpt 2 response to excerpt > relevant excerpt 3 response to excerpt

or for short messages like this:

> entire message response to message

Thanks to poor design of some PC-based mail agents, one will occasionally see the entire quoted message *after* the response, like this

response to message > entire message

but this practice is strongly deprecated.

Though `>' remains the standard inclusion leader, `|' is occasionally used for extended quotations where original variations in indentation are being retained (one mailer even combines these and uses `|>'). One also sees different styles of quoting a number of authors in the same message: one (deprecated because it loses information) uses a leader of `> ' for everyone, another (the most common) is `> > > > ', `> > > ', etc. (or `>>>> ', `>>>', etc., depending on line length and nesting depth) reflecting the original order of messages, and yet another is to use a different citation leader for each author, say `> ', `: ', `| ', `} ' (preserving nesting so that the inclusion order of messages is still apparent, or tagging the inclusions with authors' names). Yet *another* style is to use each poster's initials (or login name) as a citation leader for that poster.

Occasionally one sees a `# ' leader used for quotations from authoritative sources such as standards documents; the intended allusion is to the root prompt (the special Unix command prompt issued when one is running as the privileged super-user).

Hacker Speech Style:

Hackish speech generally features extremely precise diction, careful word choice, a relatively large working vocabulary, and relatively little use of contractions or street slang. Dry humor, irony, puns, and a mildly flippant attitude are highly valued -- but an underlying seriousness and intelligence are essential. One should use just enough jargon to communicate precisely and identify oneself as a member of the culture; overuse of jargon or a breathless, excessively gung-ho attitude is considered tacky and the mark of a loser.

This speech style is a variety of the precisionist English normally spoken by scientists, design engineers, and academics in technical fields. In contrast with the methods of jargon construction, it is fairly constant throughout hackerdom.

It has been observed that many hackers are confused by negative questions -- or, at least, that the people to whom they are talking are often confused by the sense of their answers. The problem is that they have done so much programming that distinguishes between

if (going) ...

and

if (!going) ...

that when they parse the question "Aren't you going?" it seems to be asking the opposite question from "Are you going?", and so merits an answer in the opposite sense. This confuses English-speaking non-hackers because they were taught to answer as though the negative part weren't there. In some other languages (including Russian, Chinese, and Japanese) the hackish interpretation is standard and the problem wouldn't arise. Hackers often find themselves wishing for a word like French `si' or German `doch' with which one could unambiguously answer `yes' to a negative question.

For similar reasons, English-speaking hackers almost never use double negatives, even if they live in a region where colloquial usage allows them. The thought of uttering something that logically ought to be an affirmative knowing it will be misparsed as a negative tends to disturb them.

In a related vein, hackers sometimes make a game of answering questions containing logical connectives with a strictly literal rather than colloquial interpretation. A non-hacker who is indelicate enough to ask a question like "So, are you working on finding that bug *now* or leaving it until later?" is likely to get the perfectly correct answer "Yes!" (that is, "Yes, I'm doing it either now or later, and you didn't ask which!").

International Style:

Although the Jargon File remains primarily a lexicon of hacker usage in American English, we have made some effort to get input from abroad. Though the hacker-speak of other languages often uses translations of jargon from English (often as transmitted to them by earlier Jargon File versions!), the local variations are interesting, and knowledge of them may be of some use to travelling hackers.

There are some references herein to `Commonwealth hackish'. These are intended to describe some variations in hacker usage as reported in the English spoken in Great Britain and the Commonwealth (Canada, Australia, India, etc. -- though Canada is heavily influenced by American usage). There is also an entry on {{Commonwealth Hackish}} reporting some general phonetic and vocabulary differences from U.S. hackish.

Hackers in Western Europe and (especially) Scandinavia report that they often use a mixture of English and their native languages for technical conversation. Occasionally they develop idioms in their English usage that are influenced by their native-language styles. Some of these are reported here.

On the other hand, English often gives rise to grammatical and vocabulary mutations in the native language. For example, Italian hackers often use the nonexistent ve