Four years ago, when YouTube implemented early support for HTML5, it wrote, "There's been a lot of discussion lately about whether or not the HTML5
YouTube said that a number of "key technologies" have enabled the switch to the new default format, including MediaSource Extensions that allow Adaptive Bitrate (ABR) streaming, which lets it adjust resolution and bitrate of video streams on the fly "in the face of changing network conditions," the open VP9 codec that enables higher resolution at lower bandwidths, Encrypted Media Extensions, new fullscreen APIs, and more.
"These advancements have benefited not just YouTube’s community, but the entire industry," YouTube wrote. "Other content providers like Netflix and Vimeo, as well as companies like Microsoft and Apple have embraced HTML5 and been key contributors to its success. By providing an open standard platform, HTML5 has also enabled new classes of devices like Chromebooks and Chromecast."
The sentimental part of me that still thinks of it as Macromedia Flash is a little bit sad to see such a venerable piece of software coming to its inevitable end; but the part of me that flips out every time the Flash plug-in crashes in Firefox will be happy to see it go. And in the end, despite the teething pains that will almost certainly accompany this transition, that's the part I'm going with. Bye-bye, Flash. Don't let the door hit you in the ass on the way out.