In my opinion, one of the most useable of the free biased Global Illumination renderer is Yafaray. You can now choose to use Yafaray, either with Blender 3D or Truespace. However, Yafaray does not comes with default settings that make good renderings.
For this article, we will focus on some Yafaray settings that aid in giving reasonable results. This screenshots below pertain to Yafaray for Blender 2.4X.