Portable C Compiler

 PCC is a small, simple, fast and understandable C99 compiler based on the
 original Portable C Compiler by S. C. Johnson, written in the late 1970s.
 Focus on being able to compile and run on a PDP11, even if it may not happen
 in reality, keeps it lean; abstinence from over-complicated algorithms leads
 to quick reliable code generation. Even though much of the compiler has been
 rewritten, some of the basics still remain.