YouTube announced today they will use the HTML5 <video> format by default in most modern browsers -- that includes Chrome, IE 11, Safari 8 and beta versions of Firefox. Why the wait? Well, YouTube says in a blog post that it was waiting for HTML5 to mature and improve. HTML5, is also resident in most streaming devices and Smart TV's. The primary reason given was a lack of Adaptive Bitrate (ABR) support, which reduces buffering. YouTube stated "ABR is part of the suite of MediaSource Extensions, which enables live streaming on game consoles and devices such as the Chromecast, in addition to standard web browsers. YouTube reports that ABR reduces buffering by over 50 percent globally, and 80 percent on "heavily-congested networks." Looks like it's the last nail in the Adobe coffin. For more info, jump over to the YouTube Developers Blog.