The Open On-Chip Debugger
Z80 shared library including some nice test-projects
A Serial Terminal Console for development on a remote (Forth) device
An open source filesystem library
Minimalistic C library for CP/M
UNIX/LINUX and legal homebrew software on the xbox360 gaming console
Pattern-based multi/many-core parallel programming framework
A UNIX-like kernel for the i386 architecture
Homebrew toolchains for wii, gamecube, 3ds, ds, gba, gp32 and psp
AOSP-based Operating System (On phone tap on "Try to download anyway")
Sap files player for DOS
Graphics mode console I/O for the TRS-80 Color Computer
Complete, Fast, Accurate, Game Boy/CGB/SGB Emulator.
A new simple operating system