Raymond,
Ruby + OpenGL works great (comes w/ windows installer too).
I've only done very basic GL apps so far.. most amusing thing was a
small partical system .. spewing colored dots from under the mouse
cursor and then causing them to blow around on window. Very basic,
very silly, but really amusing because it 'Just Worked' in both Linux
(./run_it) and Windows (double click it). Actually getting the linux
to work was a bit harder since I had to install the opengl bindings.
Other fun gl related stuff
http://rubyforge.org/projects/rubyglew/
http://librend.rubyforge.org/wiki/wiki.pl
librend is a really interesting looking project.. but at this time
only is going to work in Linux land.. and only if you are willing to
dedicate a lot of time towards getting all of its dependancies (both
in ruby and out) compiled and working.. but the end result is
amazing... the following is all the code needed to make a anti-aliased
true-type opengl clock:
http://rafb.net/paste/results/pw8XY150.html
Fun stuff!
-dayne