It took me a while to find this file. I just stumbled across it. Like previous versions of Avastar had a free ‘workbench’ file for non-Avastar users there is a similar file now for Fitted Mesh. See: Machinimatrix Fitted Mesh Survival Kit.
This file looks complex if you haven’t seen an Avastar file before. Gaia Clary has a text object in the ‘blend’ file that explains the file’s layout. When you open the blend file load the UI (box in ‘file open’ usually checked by default) to see a layout like I show in the image above. This will expose the more important parts of the file.
The Tool Shelf section I labeled ‘A’ is an Avastar feature. The Properties Panel on the right that I have labeled ‘B’ is a standard Blender panel that does the same things. ‘A’ is a shortcut for ‘B’ that makes things more intuitive for Avastar users.
Any Blender user without Avastar can do anything an Avastar user can. But, it is going to take way less learning and far fewer clicks with Avastar. So, the text section gives non-Avastar users the information supplied by section ‘A’.
Avastar does have a modified Collada export that does a number of translations for you to create a SL compatible Collada file. You have to walk that mine field if you do a plain Blender Collada export.