Pixie is a free (open source), photorealisticraytracing renderer for generating photorealistic images, developed by Okan Arikan in the Department of Computer Science at The University of Texas At Austin. It is RenderMan-compliant (meaning it reads conformant RIB, and supports full SL shading language shaders) and is based on the Reyes rendering architecture, but also support raytracing for hidden surface determination.
Like the proprietary BMRT, Pixie is popular with students learning the RenderMan Interface, and is a suitable replacement for it. Contributions to Pixie are facilitated by SourceForge and the Internet where it can also be downloaded free of charge as source code or precompiled. It compiles for Windows (using Visual Studio 2005), Linux and on Mac OS X (using Xcode or Unix-style configure script).
Key features include:
Fast multi-threaded execution.
Possibility to distribute the rendering process to several machines.