I finally got around to reading The Cathedral and the Bazaar, uninterrupted and in full. I’ll try to summarize the essay briefly. For the interested, there is also a decent summary on Wikipedia. If the essay is not enough for you, it has also been expanded into a book.

This 40-page essay compares two project management styles, the cathedral, where an exclusive team of the chosen few work on a project; and the bazaar, where control is decentralized, and people make contributions as they see fit. The former style is more traditional and common in the industry, and the latter style is more often seen in the open-source community. The author compares the merits of each approach and presents a successful project he deliberately ran in the bazaar style as an example.

My main take-aways from the essay were that the bazaar style can be successful and more effective at producing high-quality software in comparison to the cathedral style. Having a large number of interested, competent people look at the code gives great development momentum and debugging throughput. For this to work, though, your project must be enticing enough for people to want to work on it (the “plausible promise”). Your project also needs to be free and open-source: without this, it’s very difficult to reach potential contributors. Until your project gets to that stage, the cathedral style seems like a better way to go.

The essay is written around a series of 19 lessons, which I copy-paste below. I’ll put the points that resonated with me in particular in bold:

  1. Every good work of software starts by scratching a developer’s personal itch
  2. Good programmers know what to write. Great ones know what to rewrite (and reuse).
  3. “Plan to throw one away; you will, anyhow.” (Fred Brooks, “The Mythical Man-Month”, Chapter 11)
  4. If you have the right attitude, interesting problems will find you.
  5. When you lose interest in a program, your last duty to it is to hand it off to a competent successor.
  6. Treating your users as co-developers is your least-hassle route to rapid code improvement and effective debugging.
  7. Release early. Release often. And listen to your customers.
  8. Given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone.
  9. Smart data structures and dumb code works a lot better than the other way around
  10. If you treat your beta-testers as if they’re your most valuable resource, they will respond by becoming your most valuable resource.
  11. The next best thing to having good ideas is recognizing good ideas from your users. Sometimes the latter is better.
  12. Often, the most striking and innovative solutions come from realizing that your concept of the problem was wrong.
  13. “Perfection (in design) is achieved not when there is nothing more to add, but rather when there is nothing more to take away.”
  14. Any tool should be useful in the expected way, but a truly great tool lends itself to uses you never expected
  15. When writing gateway software of any kind, take pains to disturb the data stream as little as possible – and never throw away information unless the recipient forces you to!
  16. When your language is nowhere near Turing-complete, syntactic sugar can be your friend.
  17. A security system is only as secure as its secret. Beware of pseudo-secrets.
  18. To solve an interesting problem, start by finding a problem that is interesting to you.
  19. Provided the development coordinator has a medium at least as good as the Internet, and knows how to lead without coercion, many heads are inevitably better than one.

Linus’ Law: “Given enough eyeballs, all bugs are shallow.”