OpenTTD 2005 2009 Business Sim GPLv2 GPLv2 An open-source 'Transport Tycoon Deluxe' clone OpenTyrian 2007 2009 Scrolling shooter GPLv2 The OpenTyrian team ported the closed-source Pascal code of Tyrian to C with permission of Jason Emery. Pingus 1998 2007 Puzzle GPL GPL Inspired by Lemmings . PlaneShift 2002 2009 MMORPG LGPL