HTML5 video
Support for HTML5 video has been steadily increasing. In June 2013, Netflix added support for HTML5 video. In January 2015, YouTube switched to using HTML5 video instead of Flash by default. In December 2015, Facebook switched from Flash to HTML5 for all video content.
HTML5
HTML 5 is the fifth and current major version of the HTML standard, and subsumes XHTML. It currently exists in two standardized forms: "HTML 5.2 Recommendation" by the World Wide Web Consortium (W3C, a broad coalition of organizations), intended primarily for Web content developers; and "HTML Living Standard" by WHATWG (a small consortium of four browser vendors), intended primarily for browser developers, though it also exists in an abridged Web developer version. There are minor conflicts between the two groups' specifications.