A complete runtime environment for gcc
The Small Device C Compiler (SDCC), targeting 8-bit architectures
Scripts, Makefiles, tools helping to build TinyCC on Windows and wine.
A minimalistic but complete standard Forth compiler in C
C compiler and dev kit for the z80 with assembly language libraries.
A CBM BASIC Editor for Windows
BASIC Compiler and Interpreter
EMX compiler hosted on Win32
Full Pascal and Assembly language tool chain for Texas Instrument TI-
Implementations for the Revised Report language
Oberon family of languages to C translator for ARM, x64 and x86 archit
Mariko's GCC for the x68000
Ada cross compiler and libraries for AVR µCs
A "Just Enough Language" compiler targeting the 6502/Z80/6809
Micro Programming Language - A Portable Language for Micro Computers
Homebrew toolchains for wii, gamecube, 3ds, ds, gba, gp32 and psp
A C Compiler/Editor for Retro 6809 Machines (Colour Computer/Dragon)
Moved to https://github.com/davidgiven/ack