The Small Device C Compiler (SDCC), targeting 8-bit architectures
Open Watcom C/C++ compilers and tools Fork
multi-platform cross assembler for 6502/6510/65816 cpu
C compiler and dev kit for the z80 with assembly language libraries.
Implementations for the Revised Report language
SUNY Stony Brook Pascal for the IBM/360 written in XPL
ATasm is a 6502 command-line cross-assembler.
Ada cross compiler and libraries for AVR µCs
An open source ecosystem for IoT development
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
Supports writing Ada software for Cortex-M3, M4F boards
A C Compiler/Editor for Retro 6809 Machines (Colour Computer/Dragon)
Embed C++ in Python source code, dynamically compile and access data
C/C++ Compiler for the ActionScript Virtual Machine (AVM2)
C-Lesh is a game programming language for 2D games.