XPMCK is a music (expressed in MML) compiler kit targeted towards various video game systems. It currently supports the following systems:

* Capcom Play System (VGM output)
* Commodore 64
* Nintendo Gameboy / Gameboy Color
* SEGA Master System
* SEGA Game Gear
* SEGA Genesis

Besides the compiler and its source code, the kit includes playback libraries for all supported systems, as well as examples and brief documentation.

Changes:

Added playback code for the Commodore 64.
Added CPS-1 as a supported target (YM2151. VGM output only).
The compiler now outputs header information to be used when creating .gbs/.sid files (C64, GBC).
Volume is now applied individually per operator (Genesis).
Added support for SSG envelope generation (Genesis).

http://jiggawatt.org/muzak/xpmck/