NOX render

WHAT IS NOX?

NOX is a free stand-alone, physically-accurate state-of-an-art renderer. Its engine is based on unbiased methods. Global illumination is evaluated using Path Tracing or Bidirectional Path Tracing. Light behavior is based on laws of physics, however some simplifications occur. Many post-production actions can be done in NOX internally, so no additional software is necessary. NOX works with scenes created and imported from 3ds Max, Blender and Cinema4D.

http://www.evermotion.org/nox/overview