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 neccessary 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.
The first place to start is the manual.
Latest Release (1.0rc1)
The latest CEL release can by find on the sourceforge project page in the downloads section.
CEL comes prepackaged with a number of example applications which can be found under apps/ in the CEL package.