Crystal Space is a free cross-platform software development kit for realtime 3D graphics, with particular focus on games.
CEL (or Crystal Entity Layer) is a set of plugins and applications built on top of the Crystal Space SDK. CEL provides a set of commonly used abstractions to specifically help with writing games. CEL introduces the notion of an 'entity' which can be any kind of (visual or non-visual) object in a game. CEL also comes with a lot of useful plugins for 3rd/first person camera handling, physics, movement system, quest system, and so on.
Written in C++, CEL can also be interacted with via Python or Xml. Using CELstart it is also not necessary to use C++. This means that since the base code is C++, CEL is fast while being extremely easy to use from within Python and/or Xml.
Games in this database that use this engine: