Posted today on the Xonotic blog is why the first person shooter isn't yet on Steam. Xonotic is a very popular open-source game and being forked from Nexuiz is one of the most visually impressive open-source games. Xonotic isn't your AAA title, but its DarkPlaces-enhanced engine and creative visuals and in-game assets are much better than what you normally see from open-source games. Xonotic is also one of my favorite open-source games to use for GPU/driver benchmarking due to its visual intensity.
Xonotic developers aren't in opposition to Steam, but there's some "problems" they must solve first:
- The developers still consider the game to be in a beta stage and with bugs to be fixed. When the game is polished is when they would like to bring the title to larger audiences.
- It costs $100 USD to push a game onto Steam Greenlight. However, that isn't really much of a concern to the Xonotic developers.
- It's a myth that Steam doesn't support GPL-licensed games. Other GPL software like Blender and Warsow and Aquaria and Gish are available via Steam.
- One of the larger problems is that there's currently no free/open-source library for supporting the SteamWorks API. Valve doesn't require Steam-published titles to use SteamWorks, but then you lack many of the benefits of using Steam like statistics tracking, Steam infrastructure integration, and other features. However, Xonotic developers would likely keep using their own "XonStat" statistics component anyhow over SteamWorks support.
Xonotic developers hope to eventually release their first person shooter on Steam, but right now there's no timetable at all for reaching that milestone -- heck, we're still waiting for Xonotic 1.0 and the current stable release is several months old.