GemRB (Game engine made with pre-Rendered Background) is a portable open-source implementation of Bioware's Infinity Engine.

It was written to support pseudo-3D role playing games based on the Dungeons & Dragons ruleset (Baldur's Gate and Icewind Dale series, Planescape: Torment). It should run on GNU/Linux, Microsoft Windows, OS X, possibly other UNIX derivatives and more. It is licensed under the GPL.