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.
VP9
VP9 is implemented in these web browsers:
Internet Explorer and Apple Safari are missing VP9 support completely.
In March 2016 an estimated 65 to 75% of browsers in use on desktop and notebook systems were able to play VP9 videos in HTML5 webpages, based on data from StatCounter.