Once upon a time, during my apprenticeship in graphics, I tried to put together a graphics library for various non-dedicated cards.
I decided to begin with Matrox Millennium 2064W, for that was all I had at that time. I knew it was an excellent 2D card, and I found it had some (basic) 3D functions, too.
First, I got the sources from FreeBE/AF. Soon I discovered it wasn't what I was looking for, because no 3D functions were available at all. Though, it turned to be a great deal of information...
Then I asked permission from Matrox to get the specs for 2064W. They are really nice people, for they allowed me to download ANY specs I wanted, starting with 2064W up to G400 etc.
Finally, I started the work, combining the knowledge of FreeBE/AF with the specs. You can download the testsuite here. It features flat/gouraud/Z-flat/Z-gouraud triangles, flat/gouraud lines etc.