HTML5 video
In 2010, in the wake of Apple iPad launch and after Steve Jobs announced that Apple mobile devices would not support Flash, a number of high-profile sites began to serve H.264 HTML5 video instead of Adobe Flash for user-agents identifying as iPad. HTML5 video was not as widespread as Flash videos, though there were rollouts of experimental HTML5-based video players from DailyMotion (using Ogg Theora and Vorbis format), YouTube (using the H.264 and WebM formats), and Vimeo (using the H.264 format).
YouTube
On January 27, 2015, YouTube announced that HTML5 would be the default playback method on supported browsers. YouTube used to employ Adobe Dynamic Streaming for Flash, but with the switch to HTML5 video now streams video using Dynamic Adaptive Streaming over HTTP (MPEG-DASH), an adaptive bit-rate HTTP-based streaming solution optimizing the bitrate and quality for the available network.