Aqsis is a free rendering suite compliant with the RenderMan standard.

The Aqsis project consists of a renderer, shader compiler and a few other supporting components.

Like the original PRMan from Pixar, it is an implementation of the Reyes rendering algorithm, which is famous for its high speed and efficiency in handling even very large scenes, and has good support for displacement shaders.

Like many other open source projects, Aqsis is hosted on SourceForge and is in continuous and active development.

The MakeHuman project uses Aqsis to produce realistic renderings of the human body.