The Open Source Blender Project "Sintel" (http://sintel.org) avatar has been used in a number of open source projects and a version is available to use as an avatar or character in Unity. E.g. from http://u3d.at.ua/ where you need to register before being able to obtain the free download.
The results of the Blender Durian Open Movie project are licensed under the Creative Commons Attribution 3.0 license. This includes all the data published online and on the DVDs, and all of the contents on the sintel.org website.
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