GnuWin32 provides Win32 (MS Windows 95, 98, ME, NT, 2000, and XP)
ports of tools with a GNU or similar Open Source license.
Hu-Go! is a PC Engine Emulator for Linux/i386 under console and X11. It plays Hu cards and CDs (and various forms of dumps from them).
A secure PHP framework.
A social networking client.