Cal3D is a skeletal based 3D character animation library written in C++ in a platform-/graphic API-independent way. Originally designed to be used in a 3D client for Worldforge, it evolved into a stand-alone product which can be used in many different kinds of projects. It supports combining animations and actions through a 'mixer' interface, and work is currently underway to integrate morph targets (interpolating between one mesh and another, using the same vertex sequence) easily into the system.