On: ISO C became unusable for operating systems develo...

[yjftsjthsd-h]

You can still be portable between compilers; Linux builds with GCC and Clang, and used to build with tcc (although that probably required patches)

[zokier → yjftsjthsd-h]

Linux builds on clang after a decade of dedicated effort to make it happen, and that is with clang overall being comparatively similar to gcc (e.g clang implements many gcc extensions): https://github.com/ClangBuiltLinux/linux/wiki/Project-histor...