Silicon Graphics GL Display Language?

[ndm767]

I'm currently writing a 4D renderer as part of my high school senior thesis and I was looking at the w4 files so I don't have to write the vertices by hand. The appendix of the paper mentions something called the "Silicon Graphics GL Display Language" that the w4 files seemed to be based upon. I haven't been able to find any other mention of this on the internet and I was wondering if anyone could point me in the right direction or provide clarification. Thanks in advance!