Chaos Esque Anthology

A free 3d game for PC that does not limit the player. Fight,Build,Gain.

200+ weapons. Build-able enter-able buildings (Like an FPS RPG but with interiors) (Multi-tool/ Utili-tool). City generation (all buildings enterable). A 2 iso (6GB) exploration of what QuakeC can do. Over 100 maps included, along with map editor and sourcecode. Fully free and opensource: code and media.

A modification of Xonotic which included extended weapons, maps, vehicles, buildable buildings, mounted weapons, spell casting, monsters, player characters, textures, and game mode (such as colorwar (think liquidwar))

Source: Website