Zencoder
Zencoder is the creator of an open-source HTML5 video player, Video.js, built with Javascript, HTML, and CSS. Video.js plays video via native playback in all HTML5 browsers and devices, or through Adobe Flash when HTML5 playback is not available.
Vimeo
On October 9, 2007, Vimeo announced support for high definition playback in 1280×720 (720p), becoming the first video sharing site to support consumer HD. Uploaded HD videos were automatically converted into 720/30p VP6 Flash video. Since August 2010, all videos are encoded into H.264 for HTML5 support. All videos uploaded before were re-encoded. Non-Plus users can upload up to 500 MB of videos per week, and up to one HD video per week (additional HD videos uploaded within the same week are encoded to SD).