VideoJS is the default media player in Moodle. It is demonstrated in the screencast Media players.
VideoJS player settings, such as the supported video and audio file extensions, may be found in 'VideoJS player' in Site administration.
See Media FAQ for details on how to display YouTube subtitles and/or playlists if you are using VideoJS player.
New in 3.5: VideoJS supports RTMP links. For information for site administrators on how to format this, see How can I play RTMP video in VideoJS?