Vendetta Online is a multi-platform 3D space-combat MMO for Windows, Mac, Linux/32 and Linux/64. The game permits players to interact in a vast online galaxy; fighting, trading, and mining their way to success. A "twitch" type real-time combat model makes true player skill the deciding factor instead of character advancement. Massive capital-ship battles shake the foundations of the major nations at war, while others struggle to push back the encroachment of the AI "Hives". A no-strings free trial is available.
OpenMW is an attempt to reimplement the popular role playing game Morrowind. It aims to be a fully playable implementation of the game that will run on Linux, Windows, and Mac OS X. No game data is distributed with the code; the user must already own a copy of Morrowind to use the software.
Arx Libertatis is a cross-platform, open source port of Arx Fatalis, a 2002 first-person role-playing game developed by Arkane Studios. Arx Fatalis features crafting, melee and ranged combat, and a unique casting system where the player draws runes in real time to effect the desired spell. The Arx Libertatis source code is based on the publicly released Arx Fatalis sources. This does however not include the game data, so you need to obtain a copy of the original Arx Fatalis or its demo.
ScummVM is an interpreter and emulator for several classic graphic point-and-click adventure games. Support is currently available for: Adventure Soft's Simon the Sorcerer 1 and 2; Revolution's Beneath A Steel Sky, Broken Sword 1, and Broken Sword 2; Flight of the Amazon Queen; Wyrmkeep's Inherit the Earth; Coktel Vision's Gobliiins; and games based on LucasArts' SCUMM (Script Creation Utility for Maniac Mansion) system. The latter includes titles such as Monkey Island, Day of the Tentacle, Sam and Max, The Dig, and more.
PCGen is a Java (1.5+) -based character generator aimed at supporting OGL role playing games like those based upon the SRD, RSRD, and MSRD (such as Dungeons and Dragons). It is highly configurable by the users, allowing the Game Master to add or remove races, classes, feats, etc., and to implement house rules such as differing class or race restrictions. Level advancement is also supported, with configurable progressions of feats, skills and ability score bonuses. For "at the table" support, PCGen offers a set of GM plugins. Further options allow the user to produce a customized character sheet, which can then be viewed in, or printed from, the user's WWW browser. It can also produce a "party" sheet with the information needed by the GM.
Marauroa is a multiplayer online game framework server. It uses a multithreaded server architecture with a TCP oriented network protocol, a MySQL based persistence engine, and a flexible game system. The game system is totally expandable and modifiable by game developers and is able to run Python scripts defining the game's rules. Marauroa is based on a design philosophy called Action/Perception. Marauroa is totally game agnostic and makes very little assumptions about what are you trying to do, allowing a great freedom to create any game type.