YafaRay is a free open-source montecarlo raytracing engine released under the
LGPL 2.1 license. Raytracing is a rendering technique for generating realistic
images by tracing the path of light through a 3D scene. A render engine consists
of a specialised computer program that interacts with a host 3D application to
provide specific raytracing capabilities "on demand". The YafaRay engine can be
used in the following 3D applications: Blender, Edificius, pCon-planner and
Wings 3D.

WWW: http://www.yafaray.org/