I don't know if any of you have ever seen this renderer-
Its unbiased, leave it on enough and the image will be completly artifact-free, since it runs on the Metropolis Light Transport algorithm, which is very efficient. You can use it as a pure path-tracer, or a pure Bi-Directional Path Tracer, and these are specified in the file that comes with it.
However, you need the scene to be in .xml format and it is kinda slow, but you can download converters from the site.
I like it a lot- more than Mental Ray.
Cornell Box Test- 18 minutes
Depth Of Field Test-33 minutes
Theses are just tests that come with Indigo v0.4
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