Linux

Abe's Amazing Adventure!!
Abuse
ADOM
DRL
Falcon's Eye
Freedroid RPG
Heroes
Koules
Sqrxz
Super Crate Box
Tux Racer (Open Source)
Tux Racer (Commercial)
U.R.B.A.N. - The Cyborg Project
Zak McKracken Between Time and Space
ZBlast