1. The NURBS++ package, http://libnurbs.sourceforge.net/index.shtml .
2. NURBS Toolbox, http://www.aria.uklinux.net/nurbs.php3 .
3. NIST/IGES, http://www.nist.gov/iges/ .
4. SLC file format, http://www-rp.me.vt.edu/bohn/rp/SLC.html . Info Page: CAD/CAM, http://www.cs.cmu.edu/People/unsal/research/rapid/cadcam.html .
5. CAD Importer File Formats, http://www.actify.com/v2/products/Importers/formats.htm .