I have to jum in this discussion...
blender on IRIX interests me quite a bit, because it is a nice piece of software, because it is small and light etc etc... (also essentially the only decent 3D package you get for irix, mac, linux and windows...)
right now I am overly busy, but some months ago I tried to get involved in the irix effort. I got the nice help from guys as Hos and other chaps from the blendercoder channel, including ton himself (to be honest, ton makes always correct statements, often says true things but is rarely of real help...).
I found it very difficult to compile blender on IRIX, compared to other platforms. The configure system came in but worked badly. I think it is out again. THe whole thing is full of small things to check for if you system is not "standard". The effect that I tried to build on three or four computers with gcc 2.95, gcc3 and mipspro and rarely succeeded. I remember I got it really building only on one I think.
It is a problem with the pre-built libraries for example...
I needed this because that crappy ghost thing is full of big and small bugs on X11. Yes, the bugs affects linux and irix and solaris, but often you don't notice that on all platforms. THe problem is, there are few/no skilled developers for X11.
Specifically there is abug that causes an incredible CPU usage on IRIX with mouse position tracking, you can notice that very well on older, express based boxes. I notice it little on a 5K indy and not at all on an octane, but my indigo2 RK4 with XZ... I cn get the CPU to 100% by just moving the mouse! A pity, because even that old machine is actually better to model than my iBook (and belnder on my centrino with radeon just plainly sucks).
Thus SGIs, even if really old, are still quite nice to model in wireframe. For rendering you might move the scene elsewhere.
thus I wasn't really able to help out in blender, I was able to build and check proposed patches... but little more, I have no X11 and OpenGL coding experience. I remain open to support everyone in an unofficial way though. Currently I am not able to get official due to time constraints, not only knowledge constraints.
Then there are many small details that make blender slow on older machines or even buggy to use due to openGL differences. THings which are often even useless (I think about those stupid new menus). And generaly the new ui is "heavier". I miss some things of the old gui. I'd like a cross-breed of them.
another thing that I'd like a lot is blender classic: IRIS GL is much much faster than OpenGL on the same hardware that supports it. There is a blender version that has both binaries and runs also on irix 6.5. I tried it on my indy and my indigo2 and was impressed. Really.
getting glut to work on IrisGL? A Dream.
skywriter has that blender classic project. Imagine blender working on your 4D series, indigo1 or Crimson? wouldn't that rock?
running blender on a skywriter?
skywriter is a very nice chap, but in 2 years I was never able to do anything with him. He has a chronical lack of time and old blender sources are a bit out of order. ANyway I still hoep that we can get together and spur interest in other peoples.
if possible, both paths could be walked: keep new blenders on irix as long as possible (as long as opengl 1.1 can be used or 1.2...) and our own blender fork, starting from an old version and then maybe updating it here and there with interesting new stuff (raytracer, some new UI things, subdiv. surfaces.... and other cool things that got in in blender 2.x) and leaving out useless stuff.
have fun and feel free to contact me for any development help. But don't ask too much