Firefox is now using the Azure API for HTML5 Canvas on all platforms. Azure is a new stateless 2D graphics API that Mozilla has been working on to eventually replace Cairo, the ancient graphics API currently in use.
Azure is not quite ready to make Cairo obsolete, which is why Mozilla is starting small, only using it for the canvas element, granted, the most complex element, graphics wise. In the future though, Azure may start taking over more tasks.
"As of tonight, Azure canvas is on by default on all platforms! The last platform to get turned on was Linux, for which Anthony Jones did a lot of work on performance to bring Azure canvas up to par with Thebes, and exceed it in some cases. In the next cycle we will get to remove Thebes canvas from the code-base altogether," Mozilla's Nick Cameron wrote
For more than a year now, Firefox has been working on revamping its graphics engine. Given how taxing web apps are becoming, a fast and efficient graphics engine, that can leverage the GPU, is a must for all browsers. IE was the first to make a big fuss out of it and then everyone followed.
But things quieted down after a while. In fact, Opera 12 which was supposed to be the first browser to be fully 3D accelerated, at every level, came out with hardware acceleration disabled by default, because of performance issues.
With Firefox, things are more complicated. Firefox suffers from depending on a code base that goes back more than a decade in some ways.
Major components can't just be updated or replaced without affecting everything else. And you can't just do a full revamp on a project the size of Firefox, not unless you're asking for trouble. The only update path is to gradually improve the various internal components.
Which is why Mozilla decided to use Azure only for the Canvas element. That has now been achieved.
At this point, Azure is used on Firefox OS, Android and Linux - with a Cairo backend, Mac with a Quartz backend, and Windows - with Direct2D on Vista and 7, provided your graphics card and drivers are up-to-date, i.e. they're not blacklisted.
Windows XP and those with old drivers get a Cairo backend. On some platforms, Azure is only enabled in the Nightly or Aurora builds. You can find out more about Azure here