Oh, here's a couple more I forgot about: nwcc: small, slightly unfinished, looks like it's stalled. sparse: technically this isn't a compiler, it's a code lin

Oh, here's a couple more I forgot about: nwcc: small, slightly unfinished, looks like it's stalled. sparse: technically this isn't a compiler, it's a code linter --- but it contains a complete ANSI C front end and a reasonable amount of a backend and can be made to generate code without much effort. I've used it to compile C to Java and Perl. There's no optimisation layer and it's a little buggy (it's not really really intended as a compiler).