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).
HuC is a PC Engine C compiler. It can create ROMs (hucard) or CD images and is bundled with an assembler and all kinds of libraries. You can ouput text, scrolls, make sound, control CD, handle sprites and tiles, and more.
The Horde task list manager.
A patch manager and difference viewer.