Neverwinter Nights

From Wikipedia

Neverwinter Nights (NWN), produced by BioWare and published by Infogrames (now Atari), is a third-person perspective computer role-playing game that is based on third edition Dungeons & Dragons and Forgotten Realms rules. It was originally to be published by Interplay Entertainment, but the publisher's financial difficulties forced the change. Infogrames released Neverwinter Nights for Windows on June 18, 2002. BioWare released the freely downloadable Linux Client in June 2003 (purchase of game still required). MacSoft released a Mac OS X port in August 2003. Two expansion packs were released in mid and late 2003, and a third in 2005. On October 31, 2006, the sequel Neverwinter Nights 2 was released followed by its first expansion in late 2007 and its second one at the end of 2008. The game was based on the concept of building an internet-like model for a massively multiplayer game, allowing the end users to host the server. The belief was this model would create a potentially infinite massively multiplayer game framework.

The core release includes the game engine, a campaign that can be played as single player or multiplayer, and the Aurora toolset (for Windows only) used for creating custom content based on the same engine.