Just to continue the catalogue:<p>pcc is simple, but very old school and a bit contorted.<p>libfirm is small and clean and generates excellent code. (Despite the name, it&#x27;s a complete ANSI C compiler, as well as being a LLVM-light.)<p>The ACK is easy to port and is a complete standalone toolchain including compilers, assemblers and linkers, but (at least on modern processors) produces code so bad that it will make you want to stab yourself in the eyes to make the pain go away.<p>There&#x27;s a look-but-don&#x27;t-touch licensed compiler called vbcc which is by far the best C compiler I&#x27;ve ever seen; small, easy to understand, easy to port, and produces excellent code... but the author doesn&#x27;t want to release it under an open source license.<p>Any others?