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.
VP8
Opera, Firefox, Chrome, and Chromium support playing VP8 video in HTML5 video tag. Internet Explorer officially supports VP8 with a separate codec.
According to Google VP8 is mainly used in connection with WebRTC and as a format for short looped animations, as a replacement for the Graphics Interchange Format (GIF).