Sving is a Python plugin for Blender3d that allows the exporting of Second Life Sculpted Prims.
It is also maintenance fork of the GPL'd JASS-Pro, which is in turn based on Primstar.
The goal is to provide an Internet accessible repository of the current version of JASS' and Primstar's source code. Any new patches merged here will be forwarded upstream, and any patches submitted will be reviewed and merged.
Sving is not affiliated with the Machinimatrix or Primstar teams.
Simply copy the 'jass' and 'primstar/primstar' folders into your scripts directory.
For Linux users, this would be ~/.blender/scripts/
For Windows users, it differs based on what version of windows you use. Google around for where to put the scripts.