WildMidi is a midi processing library and a midi player using the gus patch set.
great job! just wrote a plugin for deadbeef player, and it rocks (had to fix few bugs to make it work though).
VIRUS! I extracted the program, started to run it, and all of a sudden my Anti-Virus pops up with "THREAT DETECTED!" I thought it was a mistake, so I removed the file and re-extracted it. The same thing happened twice. Please be aware when downloading.