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).
HTML5
XML documents must be served with an XML Internet media type (often called "MIME type") such as codice_2 or codice_3, and must conform to strict, well-formed syntax of XML. XHTML 5 is simply XML-serialized HTML 5 data (that is, HTML 5 constrained to XHTML's strict requirements, e.g., not having any unclosed tags), sent with one of XML media types. HTML that has been written to conform to both the HTML and XHTML specifications  and which will therefore produce the same DOM tree whether parsed as HTML or XML is known as Polyglot markup