The Small Device C Compiler (SDCC), targeting 8-bit architectures
A complete runtime environment for gcc
Linux to DJGPP cross-compiler with pthread library and std::thread.
A minimalistic but complete standard Forth compiler in C
EMX compiler hosted on Win32
BASIC Compiler and Interpreter
Oberon family of languages to C translator for ARM, x64 and x86 archit
Cygwin cross-compiler for Fedora
K&R C compiler for the 68000
Homebrew toolchains for wii, gamecube, 3ds, ds, gba, gp32 and psp
A C Compiler/Editor for Retro 6809 Machines (Colour Computer/Dragon)
*** Moved to http://github.com/esumii/min-caml ***
Port of Gnat ADA to embedded ARM targets