It sounds like 3ddesktop is badly broken.  Or maybe one of the libraries
that it uses.

Software should *never* require accelerated OpenGL.  First, "fast enough"
is entirely in the opinion of the user.  Second, the speed of software
(or for that matter, hardware) rendering is going to depend on exactly what
kind of system you have.

It really takes a special kind of stupidity, IMHO, to write code that fails
just because something is believed to be "hardware" or "software" supported.
But the 3ddesktop people may not respond well to being told that.  (^&

I'd suggest finding out exactly where this test is done, patching the code
to skip the test, and using send-pr to submit the fix to the pkgsrc people.

-- 
  "I probably don't know what I'm talking about."  http://www.olib.org/~rkr/