SDK for avatars (such as Wii, XBOX 360 avatars)
looks like lile miieditor.com was closed by Nintendo ..
there is some info here on the Mii editors .. there is some source code .. not much to worry about ..
and then there is the MakeHuman project which is a completely different side of the spectrum :)
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The November XDK (Xbox Developer Kit) contains the avatar API, but its use is limited to what I understand. The game using it must be rated E. Getting access to the XDK is not easy or cheap.
Another option is XNA development, but the avatar functionality is not yet available. It has already been submitted as a proposal, but at the moment there is no information on whether or when it will be available.
EDIT: Just re-read the post and realize you are looking for an alternative. I am not aware of any pre-made packages and will most likely require you to make your own.
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