1. Kitware Inc., 28 Corporate Drive, Suite 204, Clifton Park, New York 12065. The Visualization Toolkit. http://www.kitware.com [September 2007].
2. Mercury Computer Systems Inc., Chelmsford, MA. Open Inventor from Mercury. http://www.mc.com [September 2007].
3. TGS Inc. (Template Graphics Software), San Diego, CA. Open Inventor from TGS. http://www.tgs.com [September 2007].
4. Systems in Motion (SIM) AS, Bygdøy allé 5, Oslo, Norway. Coin3D. http://www.sim.no [September 2007].
5. Tech Soft America (TSA), Oakland, CA. Hoops 3D. http://www.hoops3D.com [September 2007].