The source is primarily in C, but the idea behind the techniques is obviously the same.
old link: http ://www.magic-software.com/
The "magic-software" link above is no longer available.
The link worked, thanks a bunch.
Found many documentation files that will aid greatly in 3D programming.
rolow
www.2cwp.com
The SourceCode.html is no longer available...
www.geometrictools.com already exists.