mozplugger has long played every media format ever by hooking into system ffmpeg/mplayer tooling, on firefox/iceweasel. likewise most minimalist webkit wrapers (midori, surf) just seem to use gstreamer/ffmpeg too, which has clean-roomed free support of even nasty old codecs like realvideo. arguing over what is officialy 'shipped' when the browser supports plugins, Xembed and so on is kind of a pointless tempest in a teapot