Aqsis

Aqsis is a cross-platform photorealistic 3D rendering solution, adhering to the RenderMan interface standard defined by Pixar Animation Studios.
The Aqsis project itself consists of a number of components, each separate in their own right, but contributing to the larger aims of the project as a whole.

At this time, there are two such components, the aqsis rendering tools, and the RIBMosaic exporter for Blender.