Sources available of the K&R C compilator PhrozenC by NoRecess
-PhrozenC v1.0 is a K&R C compiler (Dennis Ritchie and Brian Kernighan, it's not ANSI C) for Amstrad CPC and PC by NoRecess. On PC it compiles a .C file in .ASM ready to compile with WinAPE. On CPC the .ASM file can be compiled with Maxam.
The source code of PhrozenC is available on Bitbucket.
For Amstrad CPC it exists a ROM version (prefer this version), a 64 Kb version (stand-alone application) and 128 Ko version (RSX).
PhrozenC is released with a PDF manual covering all the things you have to know about to start programming using PhrozenC.
There is even a small tutorial about learning C for the newcomers. Example sources are available, as also a small set of library files handling file management, graphics, memory management, string concatenation, etc...