The Thea Renderer is now available in a free beta version, available for Windows, Linux, and Mac OSX.  The beta has watermarks and a resolution limit, but is completely functional otherwise.

Finally, we are here! Thea Render has reached a level that we can safely move forward and publish our work. Our new site has been deployed although there will be improvements and changes in the next weeks for better integration. We want to thank all for your patience and support and we hope that you are going to like Thea and Plugins. We will be waiting for your feedback in the development forums and of course, we are going to answer any question you may have.

They offer plugins for 3ds Max, Blender, Cinema4D, Sketchup, and SoftImage.  Try it out, and if you like it then you can buy the Render for only 161 €.

Thea Render.