They answer the question about Chrome in the FAQ at the end now: "You Are Counting Chrome as Supporting H.264 Even Though They Dropped Support! In January 201

They answer the question about Chrome in the FAQ at the end now: "You Are Counting Chrome as Supporting H.264 Even Though They Dropped Support! In January 2011, they announced that H.264 support would be dropped. As of January 2012, Chrome has not yet dropped support for H.264." Regarding the figures, they look anomalous until you realise that IE8 and older don't support HTML5 video at all, and that the figures for browsers that do have a lot of overlap because most recent browsers support multiple video formats. Since H.264 via Flash is excluded, so are older IE browsers, and IE9 has a much smaller market share than IE as a whole, which explains why the side with Firefox on it works out a bit bigger than the side with IE on it in your comparison there.