It's usable but not polished yet. Lots of GNU extensions and an integrated assembler were added. You can read about them here: https://github.com/jart/cosmopolitan/blob/master/third_party... I have automated tests which do a two-stage build and test on every platform each time I run make, so it's going to stay stable. The two other things I want are an integrated linker and VLA parameters. Rui is helping me implement those. So I anticipate we can start distributing a APE build of complete chibicc toolchain very soon that you can use to build APE binaries on any platform.

Keep in mind this compiler doesn't optimize. So if you're OK taking a 2x performance hit, you're going to find that your code compiles significantly faster than GCC or Clang and you're going to have the convenience of the fact that the whole toolchain will be a single .com file that you can just scp on any server for a fully deterministic reproducible build experience. It's also the most readable and hackable compiler codebase I've ever seen, so if you've ever wanted to pull out the dragon book at try your hand at optimizing, you'll find that chibicc is fertile ground to do it.