| what is the random number? | |
| ``` | |
| May 2006(This essay is derived from a keynote at Xtech.)Could you reproduce Silicon Valley elsewhere, or is there something | |
| unique about it?It wouldn't be surprising if it were hard to reproduce in other | |
| countries, because you couldn't reproduce it in most of the US | |
| either. What does it take to make a silicon valley even here?What it takes is the right people. If you could get the right ten | |
| thousand people to move from Silicon Valley to Buffalo, Buffalo | |
| would become Silicon Valley. | |
| [1]That's a striking departure from the past. Up till a couple decades | |
| ago, geography was destiny for cities. All great cities were located | |
| on waterways, because cities made money by trade, and water was the | |
| only economical way to ship.Now you could make a great city anywhere, if you could get the right | |
| people to move there. So the question of how to make a silicon | |
| valley becomes: who are the right people, and how do you get them | |
| to move?Two TypesI think you only need two kinds of people to create a technology | |
| hub: rich people and nerds. They're the limiting reagents in the | |
| reaction that produces startups, because they're the only ones | |
| present when startups get started. Everyone else will move.Observation bears this out: within the US, towns have become startup | |
| hubs if and only if they have both rich people and nerds. Few | |
| startups happen in Miami, for example, because although it's full | |
| of rich people, it has few nerds. It's not the kind of place nerds | |
| like.Whereas Pittsburgh has the opposite problem: plenty of nerds, but | |
| no rich people. The top US Computer Science departments are said | |
| to be MIT, Stanford, Berkeley, and Carnegie-Mellon. MIT yielded | |
| Route 128. Stanford and Berkeley yielded Silicon Valley. But | |
| Carnegie-Mellon? The record skips at that point. Lower down the | |
| list, the University of Washington yielded a high-tech community | |
| in Seattle, and the University of Texas at Austin yielded one in | |
| Austin. But what happened in Pittsburgh? And in Ithaca, home of | |
| Cornell, which is also high on the list?I grew up in Pittsburgh and went to college at Cornell, so I can | |
| answer for both. The weather is terrible, particularly in winter, | |
| and there's no interesting old city to make up for it, as there is | |
| in Boston. Rich people don't want to live in Pittsburgh or Ithaca. | |
| So while there are plenty of hackers who could start startups, | |
| there's no one to invest in them.Not BureaucratsDo you really need the rich people? Wouldn't it work to have the | |
| government invest in the nerds? No, it would not. Startup investors | |
| are a distinct type of rich people. They tend to have a lot of | |
| experience themselves in the technology business. This (a) helps | |
| them pick the right startups, and (b) means they can supply advice | |
| and connections as well as money. And the fact that they have a | |
| personal stake in the outcome makes them really pay attention.Bureaucrats by their nature are the exact opposite sort of people | |
| from startup investors. The idea of them making startup investments | |
| is comic. It would be like mathematicians running Vogue-- or | |
| perhaps more accurately, Vogue editors running a math journal. | |
| [2]Though indeed, most things bureaucrats do, they do badly. We just | |
| don't notice usually, because they only have to compete against | |
| other bureaucrats. But as startup investors they'd have to compete | |
| against pros with a great deal more experience and motivation.Even corporations that have in-house VC groups generally forbid | |
| them to make their own investment decisions. Most are only allowed | |
| to invest in deals where some reputable private VC firm is willing | |
| to act as lead investor.Not BuildingsIf you go to see Silicon Valley, what you'll see are buildings. | |
| But it's the people that make it Silicon Valley, not the buildings. | |
| I read occasionally about attempts to set up "technology | |
| parks" in other places, as if the active ingredient of Silicon | |
| Valley were the office space. An article about Sophia Antipolis | |
| bragged that companies there included Cisco, Compaq, IBM, NCR, and | |
| Nortel. Don't the French realize these aren't startups?Building office buildings for technology companies won't get you a | |
| silicon valley, because the key stage in the life of a startup | |
| happens before they want that kind of space. The key stage is when | |
| they're three guys operating out of an apartment. Wherever the | |
| startup is when it gets funded, it will stay. The defining quality | |
| of Silicon Valley is not that Intel or Apple or Google have offices | |
| there, but that they were started there.So if you want to reproduce Silicon Valley, what you need to reproduce | |
| is those two or three founders sitting around a kitchen table | |
| deciding to start a company. And to reproduce that you need those | |
| people.UniversitiesThe exciting thing is, all you need are the people. If you could | |
| attract a critical mass of nerds and investors to live somewhere, | |
| you could reproduce Silicon Valley. And both groups are highly | |
| mobile. They'll go where life is good. So what makes a place good | |
| to them?What nerds like is other nerds. Smart people will go wherever other | |
| smart people are. And in particular, to great universities. In | |
| theory there could be other ways to attract them, but so far | |
| universities seem to be indispensable. Within the US, there are | |
| no technology hubs without first-rate universities-- or at least, | |
| first-rate computer science departments.So if you want to make a silicon valley, you not only need a | |
| university, but one of the top handful in the world. It has to be | |
| good enough to act as a magnet, drawing the best people from thousands | |
| of miles away. And that means it has to stand up to existing magnets | |
| like MIT and Stanford.This sounds hard. Actually it might be easy. My professor friends, | |
| when they're deciding where they'd like to work, consider one thing | |
| above all: the quality of the other faculty. What attracts professors | |
| is good colleagues. So if you managed to recruit, en masse, a | |
| significant number of the best young researchers, you could create | |
| a first-rate university from nothing overnight. And you could do | |
| that for surprisingly little. If you paid 200 people hiring bonuses | |
| of $3 million apiece, you could put together a faculty that would | |
| bear comparison with any in the world. And from that point the | |
| chain reaction would be self-sustaining. So whatever it costs to | |
| establish a mediocre university, for an additional half billion or | |
| so you could have a great one. | |
| Random number is 23. | |
| [3]PersonalityHowever, merely creating a new university would not be enough to | |
| start a silicon valley. The university is just the seed. It has | |
| to be planted in the right soil, or it won't germinate. Plant it | |
| in the wrong place, and you just create Carnegie-Mellon.To spawn startups, your university has to be in a town that has | |
| attractions other than the university. It has to be a place where | |
| investors want to live, and students want to stay after they graduate.The two like much the same things, because most startup investors | |
| are nerds themselves. So what do nerds look for in a town? Their | |
| tastes aren't completely different from other people's, because a | |
| lot of the towns they like most in the US are also big tourist | |
| destinations: San Francisco, Boston, Seattle. But their tastes | |
| can't be quite mainstream either, because they dislike other big | |
| tourist destinations, like New York, Los Angeles, and Las Vegas.There has been a lot written lately about the "creative class." The | |
| thesis seems to be that as wealth derives increasingly from ideas, | |
| cities will prosper only if they attract those who have them. That | |
| is certainly true; in fact it was the basis of Amsterdam's prosperity | |
| 400 years ago.A lot of nerd tastes they share with the creative class in general. | |
| For example, they like well-preserved old neighborhoods instead of | |
| cookie-cutter suburbs, and locally-owned shops and restaurants | |
| instead of national chains. Like the rest of the creative class, | |
| they want to live somewhere with personality.What exactly is personality? I think it's the feeling that each | |
| building is the work of a distinct group of people. A town with | |
| personality is one that doesn't feel mass-produced. So if you want | |
| to make a startup hub-- or any town to attract the "creative class"-- | |
| you probably have to ban large development projects. | |
| When a large tract has been developed by a single organization, you | |
| can always tell. | |
| [4]Most towns with personality are old, but they don't have to be. | |
| Old towns have two advantages: they're denser, because they were | |
| laid out before cars, and they're more varied, because they were | |
| built one building at a time. You could have both now. Just have | |
| building codes that ensure density, and ban large scale developments.A corollary is that you have to keep out the biggest developer of | |
| all: the government. A government that asks "How can we build a | |
| silicon valley?" has probably ensured failure by the way they framed | |
| the question. You don't build a silicon valley; you let one grow.NerdsIf you want to attract nerds, you need more than a town with | |
| personality. You need a town with the right personality. Nerds | |
| are a distinct subset of the creative class, with different tastes | |
| from the rest. You can see this most clearly in New York, which | |
| attracts a lot of creative people, but few nerds. | |
| [5]What nerds like is the kind of town where people walk around smiling. | |
| This excludes LA, where no one walks at all, and also New York, | |
| where people walk, but not smiling. When I was in grad school in | |
| Boston, a friend came to visit from New York. On the subway back | |
| from the airport she asked "Why is everyone smiling?" I looked and | |
| they weren't smiling. They just looked like they were compared to | |
| the facial expressions she was used to.If you've lived in New York, you know where these facial expressions | |
| come from. It's the kind of place where your mind may be excited, | |
| but your body knows it's having a bad time. People don't so much | |
| enjoy living there as endure it for the sake of the excitement. | |
| And if you like certain kinds of excitement, New York is incomparable. | |
| It's a hub of glamour, a magnet for all the shorter half-life | |
| isotopes of style and fame.Nerds don't care about glamour, so to them the appeal of New York | |
| is a mystery. People who like New York will pay a fortune for a | |
| small, dark, noisy apartment in order to live in a town where the | |
| cool people are really cool. A nerd looks at that deal and sees | |
| only: pay a fortune for a small, dark, noisy apartment.Nerds will pay a premium to live in a town where the smart people | |
| are really smart, but you don't have to pay as much for that. It's | |
| supply and demand: glamour is popular, so you have to pay a lot for | |
| it.Most nerds like quieter pleasures. They like cafes instead of | |
| clubs; used bookshops instead of fashionable clothing shops; hiking | |
| instead of dancing; sunlight instead of tall buildings. A nerd's | |
| idea of paradise is Berkeley or Boulder.YouthIt's the young nerds who start startups, so it's those specifically | |
| the city has to appeal to. The startup hubs in the US are all | |
| young-feeling towns. This doesn't mean they have to be new. | |
| Cambridge has the oldest town plan in America, but it feels young | |
| because it's full of students.What you can't have, if you want to create a silicon valley, is a | |
| large, existing population of stodgy people. It would be a waste | |
| of time to try to reverse the fortunes of a declining industrial town | |
| like Detroit or Philadelphia by trying to encourage startups. Those | |
| places have too much momentum in the wrong direction. You're better | |
| off starting with a blank slate in the form of a small town. Or | |
| better still, if there's a town young people already flock to, that | |
| one.The Bay Area was a magnet for the young and optimistic for decades | |
| before it was associated with technology. It was a place people | |
| went in search of something new. And so it became synonymous with | |
| California nuttiness. There's still a lot of that there. If you | |
| wanted to start a new fad-- a new way to focus one's "energy," for | |
| example, or a new category of things not to eat-- the Bay Area would | |
| be the place to do it. But a place that tolerates oddness in the | |
| search for the new is exactly what you want in a startup hub, because | |
| economically that's what startups are. Most good startup ideas | |
| seem a little crazy; if they were obviously good ideas, someone | |
| would have done them already.(How many people are going to want computers in their houses? | |
| What, another search engine?)That's the connection between technology and liberalism. Without | |
| exception the high-tech cities in the US are also the most liberal. | |
| But it's not because liberals are smarter that this is so. It's | |
| because liberal cities tolerate odd ideas, and smart people by | |
| definition have odd ideas.Conversely, a town that gets praised for being "solid" or representing | |
| "traditional values" may be a fine place to live, but it's never | |
| going to succeed as a startup hub. The 2004 presidential election, | |
| though a disaster in other respects, conveniently supplied us with | |
| a county-by-county | |
| map of such places. | |
| [6]To attract the young, a town must have an intact center. In most | |
| American cities the center has been abandoned, and the growth, if | |
| any, is in the suburbs. Most American cities have been turned | |
| inside out. But none of the startup hubs has: not San Francisco, | |
| or Boston, or Seattle. They all have intact centers. | |
| [7] | |
| My guess is that no city with a dead center could be turned into a | |
| startup hub. Young people don't want to live in the suburbs.Within the US, the two cities I think could most easily be turned | |
| into new silicon valleys are Boulder and Portland. Both have the | |
| kind of effervescent feel that attracts the young. They're each | |
| only a great university short of becoming a silicon valley, if they | |
| wanted to.TimeA great university near an attractive town. Is that all it takes? | |
| That was all it took to make the original Silicon Valley. Silicon | |
| Valley traces its origins to William Shockley, one of the inventors | |
| of the transistor. He did the research that won him the Nobel Prize | |
| at Bell Labs, but when he started his own company in 1956 he moved | |
| to Palo Alto to do it. At the time that was an odd thing to do. | |
| Why did he? Because he had grown up there and remembered how nice | |
| it was. Now Palo Alto is suburbia, but then it was a charming | |
| college town-- a charming college town with perfect weather and San | |
| Francisco only an hour away.The companies that rule Silicon Valley now are all descended in | |
| various ways from Shockley Semiconductor. Shockley was a difficult | |
| man, and in 1957 his top people-- "the traitorous eight"-- left to | |
| start a new company, Fairchild Semiconductor. Among them were | |
| Gordon Moore and Robert Noyce, who went on to found Intel, and | |
| Eugene Kleiner, who founded the VC firm Kleiner Perkins. Forty-two | |
| years later, Kleiner Perkins funded Google, and the partner responsible | |
| for the deal was John Doerr, who came to Silicon Valley in 1974 to | |
| work for Intel.So although a lot of the newest companies in Silicon Valley don't | |
| make anything out of silicon, there always seem to be multiple links | |
| back to Shockley. There's a lesson here: startups beget startups. | |
| People who work for startups start their own. People who get rich | |
| from startups fund new ones. I suspect this kind of organic growth | |
| is the only way to produce a startup hub, because it's the only way | |
| to grow the expertise you need.That has two important implications. The first is that you need | |
| time to grow a silicon valley. The university you could create in | |
| a couple years, but the startup community around it has to grow | |
| organically. The cycle time is limited by the time it takes a | |
| company to succeed, which probably averages about five years.The other implication of the organic growth hypothesis is that you | |
| can't be somewhat of a startup hub. You either have a self-sustaining | |
| chain reaction, or not. Observation confirms this too: cities | |
| either have a startup scene, or they don't. There is no middle | |
| ground. Chicago has the third largest metropolitan area in America. | |
| As source of startups it's negligible compared to Seattle, number 15.The good news is that the initial seed can be quite small. Shockley | |
| Semiconductor, though itself not very successful, was big enough. | |
| It brought a critical mass of experts in an important new technology | |
| together in a place they liked enough to stay.CompetingOf course, a would-be silicon valley faces an obstacle the original | |
| one didn't: it has to compete with Silicon Valley. Can that be | |
| done? Probably.One of Silicon Valley's biggest advantages is its venture capital | |
| firms. This was not a factor in Shockley's day, because VC funds | |
| didn't exist. In fact, Shockley Semiconductor and Fairchild | |
| Semiconductor were not startups at all in our sense. They were | |
| subsidiaries-- of Beckman Instruments and Fairchild Camera and | |
| Instrument respectively. Those companies were apparently willing | |
| to establish subsidiaries wherever the experts wanted to live.Venture investors, however, prefer to fund startups within an hour's | |
| drive. For one, they're more likely to notice startups nearby. | |
| But when they do notice startups in other towns they prefer them | |
| to move. They don't want to have to travel to attend board meetings, | |
| and in any case the odds of succeeding are higher in a startup hub.The centralizing effect of venture firms is a double one: they cause | |
| startups to form around them, and those draw in more startups through | |
| acquisitions. And although the first may be weakening because it's | |
| now so cheap to start some startups, the second seems as strong as ever. | |
| Three of the most admired | |
| "Web 2.0" companies were started outside the usual startup hubs, | |
| but two of them have already been reeled in through acquisitions.Such centralizing forces make it harder for new silicon valleys to | |
| get started. But by no means impossible. Ultimately power rests | |
| with the founders. A startup with the best people will beat one | |
| with funding from famous VCs, and a startup that was sufficiently | |
| successful would never have to move. So a town that | |
| could exert enough pull over the right people could resist and | |
| perhaps even surpass Silicon Valley.For all its power, Silicon Valley has a great weakness: the paradise | |
| Shockley found in 1956 is now one giant parking lot. San Francisco | |
| and Berkeley are great, but they're forty miles away. Silicon | |
| Valley proper is soul-crushing suburban sprawl. It | |
| has fabulous weather, which makes it significantly better than the | |
| soul-crushing sprawl of most other American cities. But a competitor | |
| that managed to avoid sprawl would have real leverage. All a city | |
| needs is to be the kind of place the next traitorous eight look at | |
| and say "I want to stay here," and that would be enough to get the | |
| chain reaction started.Notes[1] | |
| It's interesting to consider how low this number could be | |
| made. I suspect five hundred would be enough, even if they could | |
| bring no assets with them. Probably just thirty, if I could pick them, | |
| would be enough to turn Buffalo into a significant startup hub.[2] | |
| Bureaucrats manage to allocate research funding moderately | |
| well, but only because (like an in-house VC fund) they outsource | |
| most of the work of selection. A professor at a famous university | |
| who is highly regarded by his peers will get funding, pretty much | |
| regardless of the proposal. That wouldn't work for startups, whose | |
| founders aren't sponsored by organizations, and are often unknowns.[3] | |
| You'd have to do it all at once, or at least a whole department | |
| at a time, because people would be more likely to come if they | |
| knew their friends were. And you should probably start from scratch, | |
| rather than trying to upgrade an existing university, or much energy | |
| would be lost in friction.[4] | |
| Hypothesis: Any plan in which multiple independent buildings | |
| are gutted or demolished to be "redeveloped" as a single project | |
| is a net loss of personality for the city, with the exception of | |
| the conversion of buildings not previously public, like warehouses.[5] | |
| A few startups get started in New York, but less | |
| than a tenth as many per capita as in Boston, and mostly | |
| in less nerdy fields like finance and media.[6] | |
| Some blue counties are false positives (reflecting the | |
| remaining power of Democractic party machines), but there are no | |
| false negatives. You can safely write off all the red counties.[7] | |
| Some "urban renewal" experts took a shot at destroying Boston's | |
| in the 1960s, leaving the area around city hall a bleak wasteland, | |
| but most neighborhoods successfully resisted them.Thanks to Chris Anderson, Trevor Blackwell, Marc Hedlund, | |
| Jessica Livingston, Robert Morris, Greg Mcadoo, Fred Wilson, | |
| and Stephen Wolfram for | |
| reading drafts of this, and to Ed Dumbill for inviting me to speak.(The second part of this talk became Why Startups | |
| Condense in America.) | |
| May 2001(This article was written as a kind of business plan for a | |
| new language. | |
| So it is missing (because it takes for granted) the most important | |
| feature of a good programming language: very powerful abstractions.)A friend of mine once told an eminent operating systems | |
| expert that he wanted to design a really good | |
| programming language. The expert told him that it would be a | |
| waste of time, that programming languages don't become popular | |
| or unpopular based on their merits, and so no matter how | |
| good his language was, no one would use it. At least, that | |
| was what had happened to the language he had designed.What does make a language popular? Do popular | |
| languages deserve their popularity? Is it worth trying to | |
| define a good programming language? How would you do it?I think the answers to these questions can be found by looking | |
| at hackers, and learning what they want. Programming | |
| languages are for hackers, and a programming language | |
| is good as a programming language (rather than, say, an | |
| exercise in denotational semantics or compiler design) | |
| if and only if hackers like it.1 The Mechanics of PopularityIt's true, certainly, that most people don't choose programming | |
| languages simply based on their merits. Most programmers are told | |
| what language to use by someone else. And yet I think the effect | |
| of such external factors on the popularity of programming languages | |
| is not as great as it's sometimes thought to be. I think a bigger | |
| problem is that a hacker's idea of a good programming language is | |
| not the same as most language designers'.Between the two, the hacker's opinion is the one that matters. | |
| Programming languages are not theorems. They're tools, designed | |
| for people, and they have to be designed to suit human strengths | |
| and weaknesses as much as shoes have to be designed for human feet. | |
| If a shoe pinches when you put it on, it's a bad shoe, however | |
| elegant it may be as a piece of sculpture.It may be that the majority of programmers can't tell a good language | |
| from a bad one. But that's no different with any other tool. It | |
| doesn't mean that it's a waste of time to try designing a good | |
| language. Expert hackers | |
| can tell a good language when they see | |
| one, and they'll use it. Expert hackers are a tiny minority, | |
| admittedly, but that tiny minority write all the good software, | |
| and their influence is such that the rest of the programmers will | |
| tend to use whatever language they use. Often, indeed, it is not | |
| merely influence but command: often the expert hackers are the very | |
| people who, as their bosses or faculty advisors, tell the other | |
| programmers what language to use.The opinion of expert hackers is not the only force that determines | |
| the relative popularity of programming languages — legacy software | |
| (Cobol) and hype (Ada, Java) also play a role — but I think it is | |
| the most powerful force over the long term. Given an initial critical | |
| mass and enough time, a programming language probably becomes about | |
| as popular as it deserves to be. And popularity further separates | |
| good languages from bad ones, because feedback from real live users | |
| always leads to improvements. Look at how much any popular language | |
| has changed during its life. Perl and Fortran are extreme cases, | |
| but even Lisp has changed a lot. Lisp 1.5 didn't have macros, for | |
| example; these evolved later, after hackers at MIT had spent a | |
| couple years using Lisp to write real programs. [1]So whether or not a language has to be good to be popular, I think | |
| a language has to be popular to be good. And it has to stay popular | |
| to stay good. The state of the art in programming languages doesn't | |
| stand still. And yet the Lisps we have today are still pretty much | |
| what they had at MIT in the mid-1980s, because that's the last time | |
| Lisp had a sufficiently large and demanding user base.Of course, hackers have to know about a language before they can | |
| use it. How are they to hear? From other hackers. But there has to | |
| be some initial group of hackers using the language for others even | |
| to hear about it. I wonder how large this group has to be; how many | |
| users make a critical mass? Off the top of my head, I'd say twenty. | |
| If a language had twenty separate users, meaning twenty users who | |
| decided on their own to use it, I'd consider it to be real.Getting there can't be easy. I would not be surprised if it is | |
| harder to get from zero to twenty than from twenty to a thousand. | |
| The best way to get those initial twenty users is probably to use | |
| a trojan horse: to give people an application they want, which | |
| happens to be written in the new language.2 External FactorsLet's start by acknowledging one external factor that does affect | |
| the popularity of a programming language. To become popular, a | |
| programming language has to be the scripting language of a popular | |
| system. Fortran and Cobol were the scripting languages of early | |
| IBM mainframes. C was the scripting language of Unix, and so, later, | |
| was Perl. Tcl is the scripting language of Tk. Java and Javascript | |
| are intended to be the scripting languages of web browsers.Lisp is not a massively popular language because it is not the | |
| scripting language of a massively popular system. What popularity | |
| it retains dates back to the 1960s and 1970s, when it was the | |
| scripting language of MIT. A lot of the great programmers of the | |
| day were associated with MIT at some point. And in the early 1970s, | |
| before C, MIT's dialect of Lisp, called MacLisp, was one of the | |
| only programming languages a serious hacker would want to use.Today Lisp is the scripting language of two moderately popular | |
| systems, Emacs and Autocad, and for that reason I suspect that most | |
| of the Lisp programming done today is done in Emacs Lisp or AutoLisp.Programming languages don't exist in isolation. To hack is a | |
| transitive verb — hackers are usually hacking something — and in | |
| practice languages are judged relative to whatever they're used to | |
| hack. So if you want to design a popular language, you either have | |
| to supply more than a language, or you have to design your language | |
| to replace the scripting language of some existing system.Common Lisp is unpopular partly because it's an orphan. It did | |
| originally come with a system to hack: the Lisp Machine. But Lisp | |
| Machines (along with parallel computers) were steamrollered by the | |
| increasing power of general purpose processors in the 1980s. Common | |
| Lisp might have remained popular if it had been a good scripting | |
| language for Unix. It is, alas, an atrociously bad one.One way to describe this situation is to say that a language isn't | |
| judged on its own merits. Another view is that a programming language | |
| really isn't a programming language unless it's also the scripting | |
| language of something. This only seems unfair if it comes as a | |
| surprise. I think it's no more unfair than expecting a programming | |
| language to have, say, an implementation. It's just part of what | |
| a programming language is.A programming language does need a good implementation, of course, | |
| and this must be free. Companies will pay for software, but individual | |
| hackers won't, and it's the hackers you need to attract.A language also needs to have a book about it. The book should be | |
| thin, well-written, and full of good examples. K&R is the ideal | |
| here. At the moment I'd almost say that a language has to have a | |
| book published by O'Reilly. That's becoming the test of mattering | |
| to hackers.There should be online documentation as well. In fact, the book | |
| can start as online documentation. But I don't think that physical | |
| books are outmoded yet. Their format is convenient, and the de | |
| facto censorship imposed by publishers is a useful if imperfect | |
| filter. Bookstores are one of the most important places for learning | |
| about new languages.3 BrevityGiven that you can supply the three things any language needs — a | |
| free implementation, a book, and something to hack — how do you | |
| make a language that hackers will like?One thing hackers like is brevity. Hackers are lazy, in the same | |
| way that mathematicians and modernist architects are lazy: they | |
| hate anything extraneous. It would not be far from the truth to | |
| say that a hacker about to write a program decides what language | |
| to use, at least subconsciously, based on the total number of | |
| characters he'll have to type. If this isn't precisely how hackers | |
| think, a language designer would do well to act as if it were.It is a mistake to try to baby the user with long-winded expressions | |
| that are meant to resemble English. Cobol is notorious for this | |
| flaw. A hacker would consider being asked to writeadd x to y giving zinstead ofz = x+yas something between an insult to his intelligence and a sin against | |
| God.It has sometimes been said that Lisp should use first and rest | |
| instead of car and cdr, because it would make programs easier to | |
| read. Maybe for the first couple hours. But a hacker can learn | |
| quickly enough that car means the first element of a list and cdr | |
| means the rest. Using first and rest means 50% more typing. And | |
| they are also different lengths, meaning that the arguments won't | |
| line up when they're called, as car and cdr often are, in successive | |
| lines. I've found that it matters a lot how code lines up on the | |
| page. I can barely read Lisp code when it is set in a variable-width | |
| font, and friends say this is true for other languages too.Brevity is one place where strongly typed languages lose. All other | |
| things being equal, no one wants to begin a program with a bunch | |
| of declarations. Anything that can be implicit, should be.The individual tokens should be short as well. Perl and Common Lisp | |
| occupy opposite poles on this question. Perl programs can be almost | |
| cryptically dense, while the names of built-in Common Lisp operators | |
| are comically long. The designers of Common Lisp probably expected | |
| users to have text editors that would type these long names for | |
| them. But the cost of a long name is not just the cost of typing | |
| it. There is also the cost of reading it, and the cost of the space | |
| it takes up on your screen.4 HackabilityThere is one thing more important than brevity to a hacker: being | |
| able to do what you want. In the history of programming languages | |
| a surprising amount of effort has gone into preventing programmers | |
| from doing things considered to be improper. This is a dangerously | |
| presumptuous plan. How can the language designer know what the | |
| programmer is going to need to do? I think language designers would | |
| do better to consider their target user to be a genius who will | |
| need to do things they never anticipated, rather than a bumbler | |
| who needs to be protected from himself. The bumbler will shoot | |
| himself in the foot anyway. You may save him from referring to | |
| variables in another package, but you can't save him from writing | |
| a badly designed program to solve the wrong problem, and taking | |
| forever to do it.Good programmers often want to do dangerous and unsavory things. | |
| By unsavory I mean things that go behind whatever semantic facade | |
| the language is trying to present: getting hold of the internal | |
| representation of some high-level abstraction, for example. Hackers | |
| like to hack, and hacking means getting inside things and second | |
| guessing the original designer.Let yourself be second guessed. When you make any tool, people use | |
| it in ways you didn't intend, and this is especially true of a | |
| highly articulated tool like a programming language. Many a hacker | |
| will want to tweak your semantic model in a way that you never | |
| imagined. I say, let them; give the programmer access to as much | |
| internal stuff as you can without endangering runtime systems like | |
| the garbage collector.In Common Lisp I have often wanted to iterate through the fields | |
| of a struct — to comb out references to a deleted object, for example, | |
| or find fields that are uninitialized. I know the structs are just | |
| vectors underneath. And yet I can't write a general purpose function | |
| that I can call on any struct. I can only access the fields by | |
| name, because that's what a struct is supposed to mean.A hacker may only want to subvert the intended model of things once | |
| or twice in a big program. But what a difference it makes to be | |
| able to. And it may be more than a question of just solving a | |
| problem. There is a kind of pleasure here too. Hackers share the | |
| surgeon's secret pleasure in poking about in gross innards, the | |
| teenager's secret pleasure in popping zits. [2] For boys, at least, | |
| certain kinds of horrors are fascinating. Maxim magazine publishes | |
| an annual volume of photographs, containing a mix of pin-ups and | |
| grisly accidents. They know their audience.Historically, Lisp has been good at letting hackers have their way. | |
| The political correctness of Common Lisp is an aberration. Early | |
| Lisps let you get your hands on everything. A good deal of that | |
| spirit is, fortunately, preserved in macros. What a wonderful thing, | |
| to be able to make arbitrary transformations on the source code.Classic macros are a real hacker's tool — simple, powerful, and | |
| dangerous. It's so easy to understand what they do: you call a | |
| function on the macro's arguments, and whatever it returns gets | |
| inserted in place of the macro call. Hygienic macros embody the | |
| opposite principle. They try to protect you from understanding what | |
| they're doing. I have never heard hygienic macros explained in one | |
| sentence. And they are a classic example of the dangers of deciding | |
| what programmers are allowed to want. Hygienic macros are intended | |
| to protect me from variable capture, among other things, but variable | |
| capture is exactly what I want in some macros.A really good language should be both clean and dirty: cleanly | |
| designed, with a small core of well understood and highly orthogonal | |
| operators, but dirty in the sense that it lets hackers have their | |
| way with it. C is like this. So were the early Lisps. A real hacker's | |
| language will always have a slightly raffish character.A good programming language should have features that make the kind | |
| of people who use the phrase "software engineering" shake their | |
| heads disapprovingly. At the other end of the continuum are languages | |
| like Ada and Pascal, models of propriety that are good for teaching | |
| and not much else.5 Throwaway ProgramsTo be attractive to hackers, a language must be good for writing | |
| the kinds of programs they want to write. And that means, perhaps | |
| surprisingly, that it has to be good for writing throwaway programs.A throwaway program is a program you write quickly for some limited | |
| task: a program to automate some system administration task, or | |
| generate test data for a simulation, or convert data from one format | |
| to another. The surprising thing about throwaway programs is that, | |
| like the "temporary" buildings built at so many American universities | |
| during World War II, they often don't get thrown away. Many evolve | |
| into real programs, with real features and real users.I have a hunch that the best big programs begin life this way, | |
| rather than being designed big from the start, like the Hoover Dam. | |
| It's terrifying to build something big from scratch. When people | |
| take on a project that's too big, they become overwhelmed. The | |
| project either gets bogged down, or the result is sterile and | |
| wooden: a shopping mall rather than a real downtown, Brasilia rather | |
| than Rome, Ada rather than C.Another way to get a big program is to start with a throwaway | |
| program and keep improving it. This approach is less daunting, and | |
| the design of the program benefits from evolution. I think, if one | |
| looked, that this would turn out to be the way most big programs | |
| were developed. And those that did evolve this way are probably | |
| still written in whatever language they were first written in, | |
| because it's rare for a program to be ported, except for political | |
| reasons. And so, paradoxically, if you want to make a language that | |
| is used for big systems, you have to make it good for writing | |
| throwaway programs, because that's where big systems come from.Perl is a striking example of this idea. It was not only designed | |
| for writing throwaway programs, but was pretty much a throwaway | |
| program itself. Perl began life as a collection of utilities for | |
| generating reports, and only evolved into a programming language | |
| as the throwaway programs people wrote in it grew larger. It was | |
| not until Perl 5 (if then) that the language was suitable for | |
| writing serious programs, and yet it was already massively popular.What makes a language good for throwaway programs? To start with, | |
| it must be readily available. A throwaway program is something that | |
| you expect to write in an hour. So the language probably must | |
| already be installed on the computer you're using. It can't be | |
| something you have to install before you use it. It has to be there. | |
| C was there because it came with the operating system. Perl was | |
| there because it was originally a tool for system administrators, | |
| and yours had already installed it.Being available means more than being installed, though. An | |
| interactive language, with a command-line interface, is more | |
| available than one that you have to compile and run separately. A | |
| popular programming language should be interactive, and start up | |
| fast.Another thing you want in a throwaway program is brevity. Brevity | |
| is always attractive to hackers, and never more so than in a program | |
| they expect to turn out in an hour.6 LibrariesOf course the ultimate in brevity is to have the program already | |
| written for you, and merely to call it. And this brings us to what | |
| I think will be an increasingly important feature of programming | |
| languages: library functions. Perl wins because it has large | |
| libraries for manipulating strings. This class of library functions | |
| are especially important for throwaway programs, which are often | |
| originally written for converting or extracting data. Many Perl | |
| programs probably begin as just a couple library calls stuck | |
| together.I think a lot of the advances that happen in programming languages | |
| in the next fifty years will have to do with library functions. I | |
| think future programming languages will have libraries that are as | |
| carefully designed as the core language. Programming language design | |
| will not be about whether to make your language strongly or weakly | |
| typed, or object oriented, or functional, or whatever, but about | |
| how to design great libraries. The kind of language designers who | |
| like to think about how to design type systems may shudder at this. | |
| It's almost like writing applications! Too bad. Languages are for | |
| programmers, and libraries are what programmers need.It's hard to design good libraries. It's not simply a matter of | |
| writing a lot of code. Once the libraries get too big, it can | |
| sometimes take longer to find the function you need than to write | |
| the code yourself. Libraries need to be designed using a small set | |
| of orthogonal operators, just like the core language. It ought to | |
| be possible for the programmer to guess what library call will do | |
| what he needs.Libraries are one place Common Lisp falls short. There are only | |
| rudimentary libraries for manipulating strings, and almost none | |
| for talking to the operating system. For historical reasons, Common | |
| Lisp tries to pretend that the OS doesn't exist. And because you | |
| can't talk to the OS, you're unlikely to be able to write a serious | |
| program using only the built-in operators in Common Lisp. You have | |
| to use some implementation-specific hacks as well, and in practice | |
| these tend not to give you everything you want. Hackers would think | |
| a lot more highly of Lisp if Common Lisp had powerful string | |
| libraries and good OS support.7 SyntaxCould a language with Lisp's syntax, or more precisely, lack of | |
| syntax, ever become popular? I don't know the answer to this | |
| question. I do think that syntax is not the main reason Lisp isn't | |
| currently popular. Common Lisp has worse problems than unfamiliar | |
| syntax. I know several programmers who are comfortable with prefix | |
| syntax and yet use Perl by default, because it has powerful string | |
| libraries and can talk to the os.There are two possible problems with prefix notation: that it is | |
| unfamiliar to programmers, and that it is not dense enough. The | |
| conventional wisdom in the Lisp world is that the first problem is | |
| the real one. I'm not so sure. Yes, prefix notation makes ordinary | |
| programmers panic. But I don't think ordinary programmers' opinions | |
| matter. Languages become popular or unpopular based on what expert | |
| hackers think of them, and I think expert hackers might be able to | |
| deal with prefix notation. Perl syntax can be pretty incomprehensible, | |
| but that has not stood in the way of Perl's popularity. If anything | |
| it may have helped foster a Perl cult.A more serious problem is the diffuseness of prefix notation. For | |
| expert hackers, that really is a problem. No one wants to write | |
| (aref a x y) when they could write a[x,y].In this particular case there is a way to finesse our way out of | |
| the problem. If we treat data structures as if they were functions | |
| on indexes, we could write (a x y) instead, which is even shorter | |
| than the Perl form. Similar tricks may shorten other types of | |
| expressions.We can get rid of (or make optional) a lot of parentheses by making | |
| indentation significant. That's how programmers read code anyway: | |
| when indentation says one thing and delimiters say another, we go | |
| by the indentation. Treating indentation as significant would | |
| eliminate this common source of bugs as well as making programs | |
| shorter.Sometimes infix syntax is easier to read. This is especially true | |
| for math expressions. I've used Lisp my whole programming life and | |
| I still don't find prefix math expressions natural. And yet it is | |
| convenient, especially when you're generating code, to have operators | |
| that take any number of arguments. So if we do have infix syntax, | |
| it should probably be implemented as some kind of read-macro.I don't think we should be religiously opposed to introducing syntax | |
| into Lisp, as long as it translates in a well-understood way into | |
| underlying s-expressions. There is already a good deal of syntax | |
| in Lisp. It's not necessarily bad to introduce more, as long as no | |
| one is forced to use it. In Common Lisp, some delimiters are reserved | |
| for the language, suggesting that at least some of the designers | |
| intended to have more syntax in the future.One of the most egregiously unlispy pieces of syntax in Common Lisp | |
| occurs in format strings; format is a language in its own right, | |
| and that language is not Lisp. If there were a plan for introducing | |
| more syntax into Lisp, format specifiers might be able to be included | |
| in it. It would be a good thing if macros could generate format | |
| specifiers the way they generate any other kind of code.An eminent Lisp hacker told me that his copy of CLTL falls open to | |
| the section format. Mine too. This probably indicates room for | |
| improvement. It may also mean that programs do a lot of I/O.8 EfficiencyA good language, as everyone knows, should generate fast code. But | |
| in practice I don't think fast code comes primarily from things | |
| you do in the design of the language. As Knuth pointed out long | |
| ago, speed only matters in certain critical bottlenecks. And as | |
| many programmers have observed since, one is very often mistaken | |
| about where these bottlenecks are.So, in practice, the way to get fast code is to have a very good | |
| profiler, rather than by, say, making the language strongly typed. | |
| You don't need to know the type of every argument in every call in | |
| the program. You do need to be able to declare the types of arguments | |
| in the bottlenecks. And even more, you need to be able to find out | |
| where the bottlenecks are.One complaint people have had with Lisp is that it's hard to tell | |
| what's expensive. This might be true. It might also be inevitable, | |
| if you want to have a very abstract language. And in any case I | |
| think good profiling would go a long way toward fixing the problem: | |
| you'd soon learn what was expensive.Part of the problem here is social. Language designers like to | |
| write fast compilers. That's how they measure their skill. They | |
| think of the profiler as an add-on, at best. But in practice a good | |
| profiler may do more to improve the speed of actual programs written | |
| in the language than a compiler that generates fast code. Here, | |
| again, language designers are somewhat out of touch with their | |
| users. They do a really good job of solving slightly the wrong | |
| problem.It might be a good idea to have an active profiler — to push | |
| performance data to the programmer instead of waiting for him to | |
| come asking for it. For example, the editor could display bottlenecks | |
| in red when the programmer edits the source code. Another approach | |
| would be to somehow represent what's happening in running programs. | |
| This would be an especially big win in server-based applications, | |
| where you have lots of running programs to look at. An active | |
| profiler could show graphically what's happening in memory as a | |
| program's running, or even make sounds that tell what's happening.Sound is a good cue to problems. In one place I worked, we had a | |
| big board of dials showing what was happening to our web servers. | |
| The hands were moved by little servomotors that made a slight noise | |
| when they turned. I couldn't see the board from my desk, but I | |
| found that I could tell immediately, by the sound, when there was | |
| a problem with a server.It might even be possible to write a profiler that would automatically | |
| detect inefficient algorithms. I would not be surprised if certain | |
| patterns of memory access turned out to be sure signs of bad | |
| algorithms. If there were a little guy running around inside the | |
| computer executing our programs, he would probably have as long | |
| and plaintive a tale to tell about his job as a federal government | |
| employee. I often have a feeling that I'm sending the processor on | |
| a lot of wild goose chases, but I've never had a good way to look | |
| at what it's doing.A number of Lisps now compile into byte code, which is then executed | |
| by an interpreter. This is usually done to make the implementation | |
| easier to port, but it could be a useful language feature. It might | |
| be a good idea to make the byte code an official part of the | |
| language, and to allow programmers to use inline byte code in | |
| bottlenecks. Then such optimizations would be portable too.The nature of speed, as perceived by the end-user, may be changing. | |
| With the rise of server-based applications, more and more programs | |
| may turn out to be i/o-bound. It will be worth making i/o fast. | |
| The language can help with straightforward measures like simple, | |
| fast, formatted output functions, and also with deep structural | |
| changes like caching and persistent objects.Users are interested in response time. But another kind of efficiency | |
| will be increasingly important: the number of simultaneous users | |
| you can support per processor. Many of the interesting applications | |
| written in the near future will be server-based, and the number of | |
| users per server is the critical question for anyone hosting such | |
| applications. In the capital cost of a business offering a server-based | |
| application, this is the divisor.For years, efficiency hasn't mattered much in most end-user | |
| applications. Developers have been able to assume that each user | |
| would have an increasingly powerful processor sitting on their | |
| desk. And by Parkinson's Law, software has expanded to use the | |
| resources available. That will change with server-based applications. | |
| In that world, the hardware and software will be supplied together. | |
| For companies that offer server-based applications, it will make | |
| a very big difference to the bottom line how many users they can | |
| support per server.In some applications, the processor will be the limiting factor, | |
| and execution speed will be the most important thing to optimize. | |
| But often memory will be the limit; the number of simultaneous | |
| users will be determined by the amount of memory you need for each | |
| user's data. The language can help here too. Good support for | |
| threads will enable all the users to share a single heap. It may | |
| also help to have persistent objects and/or language level support | |
| for lazy loading.9 TimeThe last ingredient a popular language needs is time. No one wants | |
| to write programs in a language that might go away, as so many | |
| programming languages do. So most hackers will tend to wait until | |
| a language has been around for a couple years before even considering | |
| using it.Inventors of wonderful new things are often surprised to discover | |
| this, but you need time to get any message through to people. A | |
| friend of mine rarely does anything the first time someone asks | |
| him. He knows that people sometimes ask for things that they turn | |
| out not to want. To avoid wasting his time, he waits till the third | |
| or fourth time he's asked to do something; by then, whoever's asking | |
| him may be fairly annoyed, but at least they probably really do | |
| want whatever they're asking for.Most people have learned to do a similar sort of filtering on new | |
| things they hear about. They don't even start paying attention | |
| until they've heard about something ten times. They're perfectly | |
| justified: the majority of hot new whatevers do turn out to be a | |
| waste of time, and eventually go away. By delaying learning VRML, | |
| I avoided having to learn it at all.So anyone who invents something new has to expect to keep repeating | |
| their message for years before people will start to get it. We | |
| wrote what was, as far as I know, the first web-server based | |
| application, and it took us years to get it through to people that | |
| it didn't have to be downloaded. It wasn't that they were stupid. | |
| They just had us tuned out.The good news is, simple repetition solves the problem. All you | |
| have to do is keep telling your story, and eventually people will | |
| start to hear. It's not when people notice you're there that they | |
| pay attention; it's when they notice you're still there.It's just as well that it usually takes a while to gain momentum. | |
| Most technologies evolve a good deal even after they're first | |
| launched — programming languages especially. Nothing could be better, | |
| for a new techology, than a few years of being used only by a small | |
| number of early adopters. Early adopters are sophisticated and | |
| demanding, and quickly flush out whatever flaws remain in your | |
| technology. When you only have a few users you can be in close | |
| contact with all of them. And early adopters are forgiving when | |
| you improve your system, even if this causes some breakage.There are two ways new technology gets introduced: the organic | |
| growth method, and the big bang method. The organic growth method | |
| is exemplified by the classic seat-of-the-pants underfunded garage | |
| startup. A couple guys, working in obscurity, develop some new | |
| technology. They launch it with no marketing and initially have | |
| only a few (fanatically devoted) users. They continue to improve | |
| the technology, and meanwhile their user base grows by word of | |
| mouth. Before they know it, they're big.The other approach, the big bang method, is exemplified by the | |
| VC-backed, heavily marketed startup. They rush to develop a product, | |
| launch it with great publicity, and immediately (they hope) have | |
| a large user base.Generally, the garage guys envy the big bang guys. The big bang | |
| guys are smooth and confident and respected by the VCs. They can | |
| afford the best of everything, and the PR campaign surrounding the | |
| launch has the side effect of making them celebrities. The organic | |
| growth guys, sitting in their garage, feel poor and unloved. And | |
| yet I think they are often mistaken to feel sorry for themselves. | |
| Organic growth seems to yield better technology and richer founders | |
| than the big bang method. If you look at the dominant technologies | |
| today, you'll find that most of them grew organically.This pattern doesn't only apply to companies. You see it in sponsored | |
| research too. Multics and Common Lisp were big-bang projects, and | |
| Unix and MacLisp were organic growth projects.10 Redesign"The best writing is rewriting," wrote E. B. White. Every good | |
| writer knows this, and it's true for software too. The most important | |
| part of design is redesign. Programming languages, especially, | |
| don't get redesigned enough.To write good software you must simultaneously keep two opposing | |
| ideas in your head. You need the young hacker's naive faith in | |
| his abilities, and at the same time the veteran's skepticism. You | |
| have to be able to think | |
| how hard can it be? with one half of | |
| your brain while thinking | |
| it will never work with the other.The trick is to realize that there's no real contradiction here. | |
| You want to be optimistic and skeptical about two different things. | |
| You have to be optimistic about the possibility of solving the | |
| problem, but skeptical about the value of whatever solution you've | |
| got so far.People who do good work often think that whatever they're working | |
| on is no good. Others see what they've done and are full of wonder, | |
| but the creator is full of worry. This pattern is no coincidence: | |
| it is the worry that made the work good.If you can keep hope and worry balanced, they will drive a project | |
| forward the same way your two legs drive a bicycle forward. In the | |
| first phase of the two-cycle innovation engine, you work furiously | |
| on some problem, inspired by your confidence that you'll be able | |
| to solve it. In the second phase, you look at what you've done in | |
| the cold light of morning, and see all its flaws very clearly. But | |
| as long as your critical spirit doesn't outweigh your hope, you'll | |
| be able to look at your admittedly incomplete system, and think, | |
| how hard can it be to get the rest of the way?, thereby continuing | |
| the cycle.It's tricky to keep the two forces balanced. In young hackers, | |
| optimism predominates. They produce something, are convinced it's | |
| great, and never improve it. In old hackers, skepticism predominates, | |
| and they won't even dare to take on ambitious projects.Anything you can do to keep the redesign cycle going is good. Prose | |
| can be rewritten over and over until you're happy with it. But | |
| software, as a rule, doesn't get redesigned enough. Prose has | |
| readers, but software has users. If a writer rewrites an essay, | |
| people who read the old version are unlikely to complain that their | |
| thoughts have been broken by some newly introduced incompatibility.Users are a double-edged sword. They can help you improve your | |
| language, but they can also deter you from improving it. So choose | |
| your users carefully, and be slow to grow their number. Having | |
| users is like optimization: the wise course is to delay it. Also, | |
| as a general rule, you can at any given time get away with changing | |
| more than you think. Introducing change is like pulling off a | |
| bandage: the pain is a memory almost as soon as you feel it.Everyone knows that it's not a good idea to have a language designed | |
| by a committee. Committees yield bad design. But I think the worst | |
| danger of committees is that they interfere with redesign. It is | |
| so much work to introduce changes that no one wants to bother. | |
| Whatever a committee decides tends to stay that way, even if most | |
| of the members don't like it.Even a committee of two gets in the way of redesign. This happens | |
| particularly in the interfaces between pieces of software written | |
| by two different people. To change the interface both have to agree | |
| to change it at once. And so interfaces tend not to change at all, | |
| which is a problem because they tend to be one of the most ad hoc | |
| parts of any system.One solution here might be to design systems so that interfaces | |
| are horizontal instead of vertical — so that modules are always | |
| vertically stacked strata of abstraction. Then the interface will | |
| tend to be owned by one of them. The lower of two levels will either | |
| be a language in which the upper is written, in which case the | |
| lower level will own the interface, or it will be a slave, in which | |
| case the interface can be dictated by the upper level.11 LispWhat all this implies is that there is hope for a new Lisp. There | |
| is hope for any language that gives hackers what they want, including | |
| Lisp. I think we may have made a mistake in thinking that hackers | |
| are turned off by Lisp's strangeness. This comforting illusion may | |
| have prevented us from seeing the real problem with Lisp, or at | |
| least Common Lisp, which is that it sucks for doing what hackers | |
| want to do. A hacker's language needs powerful libraries and | |
| something to hack. Common Lisp has neither. A hacker's language is | |
| terse and hackable. Common Lisp is not.The good news is, it's not Lisp that sucks, but Common Lisp. If we | |
| can develop a new Lisp that is a real hacker's language, I think | |
| hackers will use it. They will use whatever language does the job. | |
| All we have to do is make sure this new Lisp does some important | |
| job better than other languages.History offers some encouragement. Over time, successive new | |
| programming languages have taken more and more features from Lisp. | |
| There is no longer much left to copy before the language you've | |
| made is Lisp. The latest hot language, Python, is a watered-down | |
| Lisp with infix syntax and no macros. A new Lisp would be a natural | |
| step in this progression.I sometimes think that it would be a good marketing trick to call | |
| it an improved version of Python. That sounds hipper than Lisp. To | |
| many people, Lisp is a slow AI language with a lot of parentheses. | |
| Fritz Kunze's official biography carefully avoids mentioning the | |
| L-word. But my guess is that we shouldn't be afraid to call the | |
| new Lisp Lisp. Lisp still has a lot of latent respect among the | |
| very best hackers — the ones who took 6.001 and understood it, for | |
| example. And those are the users you need to win.In "How to Become a Hacker," Eric Raymond describes Lisp as something | |
| like Latin or Greek — a language you should learn as an intellectual | |
| exercise, even though you won't actually use it: | |
| Lisp is worth learning for the profound enlightenment experience | |
| you will have when you finally get it; that experience will make | |
| you a better programmer for the rest of your days, even if you | |
| never actually use Lisp itself a lot. | |
| If I didn't know Lisp, reading this would set me asking questions. | |
| A language that would make me a better programmer, if it means | |
| anything at all, means a language that would be better for programming. | |
| And that is in fact the implication of what Eric is saying.As long as that idea is still floating around, I think hackers will | |
| be receptive enough to a new Lisp, even if it is called Lisp. But | |
| this Lisp must be a hacker's language, like the classic Lisps of | |
| the 1970s. It must be terse, simple, and hackable. And it must have | |
| powerful libraries for doing what hackers want to do now.In the matter of libraries I think there is room to beat languages | |
| like Perl and Python at their own game. A lot of the new applications | |
| that will need to be written in the coming years will be | |
| server-based | |
| applications. There's no reason a new Lisp shouldn't have string | |
| libraries as good as Perl, and if this new Lisp also had powerful | |
| libraries for server-based applications, it could be very popular. | |
| Real hackers won't turn up their noses at a new tool that will let | |
| them solve hard problems with a few library calls. Remember, hackers | |
| are lazy.It could be an even bigger win to have core language support for | |
| server-based applications. For example, explicit support for programs | |
| with multiple users, or data ownership at the level of type tags.Server-based applications also give us the answer to the question | |
| of what this new Lisp will be used to hack. It would not hurt to | |
| make Lisp better as a scripting language for Unix. (It would be | |
| hard to make it worse.) But I think there are areas where existing | |
| languages would be easier to beat. I think it might be better to | |
| follow the model of Tcl, and supply the Lisp together with a complete | |
| system for supporting server-based applications. Lisp is a natural | |
| fit for server-based applications. Lexical closures provide a way | |
| to get the effect of subroutines when the ui is just a series of | |
| web pages. S-expressions map nicely onto html, and macros are good | |
| at generating it. There need to be better tools for writing | |
| server-based applications, and there needs to be a new Lisp, and | |
| the two would work very well together.12 The Dream LanguageBy way of summary, let's try describing the hacker's dream language. | |
| The dream language is | |
| beautiful, clean, and terse. It has an | |
| interactive toplevel that starts up fast. You can write programs | |
| to solve common problems with very little code. Nearly all the | |
| code in any program you write is code that's specific to your | |
| application. Everything else has been done for you.The syntax of the language is brief to a fault. You never have to | |
| type an unnecessary character, or even to use the shift key much.Using big abstractions you can write the first version of a program | |
| very quickly. Later, when you want to optimize, there's a really | |
| good profiler that tells you where to focus your attention. You | |
| can make inner loops blindingly fast, even writing inline byte code | |
| if you need to.There are lots of good examples to learn from, and the language is | |
| intuitive enough that you can learn how to use it from examples in | |
| a couple minutes. You don't need to look in the manual much. The | |
| manual is thin, and has few warnings and qualifications.The language has a small core, and powerful, highly orthogonal | |
| libraries that are as carefully designed as the core language. The | |
| libraries all work well together; everything in the language fits | |
| together like the parts in a fine camera. Nothing is deprecated, | |
| or retained for compatibility. The source code of all the libraries | |
| is readily available. It's easy to talk to the operating system | |
| and to applications written in other languages.The language is built in layers. The higher-level abstractions are | |
| built in a very transparent way out of lower-level abstractions, | |
| which you can get hold of if you want.Nothing is hidden from you that doesn't absolutely have to be. The | |
| language offers abstractions only as a way of saving you work, | |
| rather than as a way of telling you what to do. In fact, the language | |
| encourages you to be an equal participant in its design. You can | |
| change everything about it, including even its syntax, and anything | |
| you write has, as much as possible, the same status as what comes | |
| predefined.Notes[1] Macros very close to the modern idea were proposed by Timothy | |
| Hart in 1964, two years after Lisp 1.5 was released. What was | |
| missing, initially, were ways to avoid variable capture and multiple | |
| evaluation; Hart's examples are subject to both.[2] In When the Air Hits Your Brain, neurosurgeon Frank Vertosick | |
| recounts a conversation in which his chief resident, Gary, talks | |
| about the difference between surgeons and internists ("fleas"): | |
| Gary and I ordered a large pizza and found an open booth. The | |
| chief lit a cigarette. "Look at those goddamn fleas, jabbering | |
| about some disease they'll see once in their lifetimes. That's | |
| the trouble with fleas, they only like the bizarre stuff. They | |
| hate their bread and butter cases. That's the difference between | |
| us and the fucking fleas. See, we love big juicy lumbar disc | |
| herniations, but they hate hypertension...." | |
| It's hard to think of a lumbar disc herniation as juicy (except | |
| literally). And yet I think I know what they mean. I've often had | |
| a juicy bug to track down. Someone who's not a programmer would | |
| find it hard to imagine that there could be pleasure in a bug. | |
| Surely it's better if everything just works. In one way, it is. | |
| And yet there is undeniably a grim satisfaction in hunting down | |
| certain sorts of bugs. | |
| ``` |