The Windows version of Firefox and Chrome have hardware accelerated canvas, how come this hasn't been done yet on Linux/Ubuntu? Is it Google/Mozilla's fault, or NVIDIA/ATI/Intel? What gives?
I can get it working on Chromium though if I do:
chromium-browser --ignore-gpu-blacklist
But that's hardly ideal and probably blacklisted for a reason.
I can't speak for Google and Mozilla, but I've worked for Opera Software, and I know what a pain it is to support OpenGL on Linux. The quality of the Linux video drivers is usually lower than on Windows, and there is more diversity (proprietary vs. open-source drivers). Plus, Linux-specific development efforts can easily get down-prioritized since the platform is less popular on desktop than Windows and MacOS.
I guess Chromium disables hardware acceleration by default for the same reason Opera currently does that: to avoid exposing users to crashes and hangs. You can enable it if you're prepared that it might not be as stable as you'd like. In fact, you'll help the browser developers if you try it and report any issues you encounter.