I think it's because Adobe doesn't really have any competitors in its marketspace (aside from Flash). Adobe's bread and butter is still the Creative Suite. It

I think it's because Adobe doesn't really have any competitors in its marketspace (aside from Flash). Adobe's bread and butter is still the Creative Suite. It doesn't view GIMP, Inkspace, etc. as a big enough threat, so why give it away for free? Microsoft on the other hand, is competing with Java for most developer mindshare (in the "conventional" space) and RoR, Django, PHP (in the "unconventional" space). Microsoft also knows that the GNU C++ compiler isn't half-bad, and additionally with the license change in Qt, it's even easier. Microsoft wants to nurture small microsoft shops in case they become big microsoft shops one day. It's a way to keep the ecosystem thriving! Once Adobe has a competitor that can compete on technical merit (and not just, "use this b/c it's free!"), then maybe Adobe can consider something similar. It's very, very, hard to compete on price. If that's your business strategy, you're going to fail in the long-run. You have to have some amount of technical innovation in your product.