iris gl?

[Luka <luka@MIT.EDU>]

what's the deal with iris gl (vs. open gl)?

there's a whole lot of code in walkthru for the purpose of supporting both.
i don't have a problem with that as long as there's a reason for it, but is
there?  when would we want/need either one of those rather than the other?

(well actually, i know we want opengl on any non-irix platform, so i guess
my question is just what's the case for iris gl?  is it a historical thing,
or something real still?  i have no idea -- educate me if you know.)

-pl