I just downloaded Firefox 40 on Linux x86 (Ubuntu 14.04) and....I don't know exactly what the boffins at Mozilla did, but they sure as hell did something...HTML5 video playback in the browser is light-years, and I mean light-years improved. My 9 year old Dell laptop absolutely choked on anything above 360p in a window. You could forget about 360p fullscreen, that was all herk and jerk. Now it plays 720p fullscreen with no problems, only 50-60% CPU usage (Core Duo). Here's to hoping that Cameron Kaiser can bring those improvements over to tenfourfox. That would be a total utter godsend to those with aging PowerMacs in 2015.