Thanks to continued improvements to start-up and first paint performance, tweaks to memory footprint and garbage collection, and the addition of a new 2D graphics backend called Azure, Firefox 8 is some 20% faster than Firefox 5 across all major metrics — and actually about equal with Chrome 14 on JavaScript and 2D rendering performance. Azure (which is new with Firefox 7) replaces Cairo, and instead of dealing with Direct2D and Quartz, it allows Firefox to deal directly with the Direct3D and OpenGL subsystems — resulting in a 20% speed boost under Windows, and probably even more under OS X.