Why OpenGL? Probably becasue it's a "standard" and well understood. That added to the fact that you can accelereate it with hardware is I guess the real reason. I guess this is the whole US/UK coding style thing of 3D right? :P For as long ago as the first read 3D games appeared on computers there were two ways of doing things. Americans relied in the main, on better hardware to speed up their code. The Brits, slaving in thier bedrooms, denied better hardware, wrote tighter code. Which, given access to better hardware, ran even faster. "a rising tide moves all ships" etc. Though for the sake of disclosure, "I am a Brit" :) I won't deny that a software renderer is usually better, but if you take an off the shelf OpenGL implementation for the preview code then the rest is so much easier to do. Take a look at D|S if you don't believe me. It's slick, fast and light. Now I have the benefit of a fast card. which makes it slicker, but compared to the new cards, it's now a little long in the tooth. What at one time was "the fastest GFX card in the world" is now commodity hardware. You can find more advanced cards in laptops... From my point of view, the transition from a PIII 700 laptop to a 2Ghz P4 made poser4 fly. The preview window fully textured was in real time. P5 made it crawl again. After all the service packs, it was on a par or slightly faster than my PIII laptop, but having seen P4 at 2Ghz, it was that that I returned too. I guess it's just a matter of people casting about the rest of the 3D world and seeing OpenGL everywhere and wanting it. This may be a hobbyist market, but the same set of people still like the look and heft of the weightier programs, even if they could never use/afford them. People "Aspire" :) The commodity argument could also be leveled against CPU's of course, the faster they get, the faster poser gets, which is something people are more likely to buy than a tricked out GFX card. I think OpenGL is quite good at what it does, however I think it works better when it's moving (so to speak) and Poser would use it for still previews :) I guess the real issue is speed. "why isn't my program that fast?" I guess that's the reason for "Why OpenGL?" later jb