I count 3 "miracles". In ascending order of awesomeness, these would be: (1) No feature creep. They provide essential functionality, little more. I say that

I count 3 "miracles". In ascending order of awesomeness, these would be: (1) No feature creep. They provide essential functionality, little more. I say that's a good thing, because if you miss functionality, the system lets you build it relatively easily. My guess is, it explains about 1 order of magnitude (it divides code volume by 10). (2) Factor everything. Again not very impressive, but it goes a long way. Just good engineering principles applied systematically across the system. For instance, they have one graphic stack, which draws everything in every program, including the window manager. They also have one document type. A side effect of this approach is a greatly increased integration. My guess is, it explains about 1 order of magnitude. (Warning: the divide between (1) and (2) is somewhat arbitrary. In some ways, the STEPS system provide more functionality than current systems. I think the trick is to stop thinking in terms of features, but in terms of capabilities. For instance, UNIX don't have a feature to sort Apache log files by IP address. But it has `sort` and `awk`, and therefore it has the capability.) (3) Build the right tools. The tools being mostly domain specific programming languages. And that is the impressive part. Their language are so expressive and simple that they can reduce code volume by two orders of magnitude without breaking a sweat. I don't know exactly how they came up with such languages, yet they did. The tree core languages that may interest you here are Ometa http://www.tinlizzie.org/ometa/ http://www.tinlizzie.org/ometa/, Maru http://piumarta.com/software/maru/ http://piumarta.com/software/maru/, and Nile. Ometa is like Lex+Yacc, only much simpler and more general (it lets you transform trees, and flatten them, which makes it suitable for all compilation stages). Maru is a not-so-inefficient self-implementing language, based on 2 cores (lambdas and objects) which can implement each other. So, 1+1+2=4. Or 1010100=10,000. I'm oversimplifying of course, but I think this gives an idea.