Dailymotion, one of the biggest video hosting sites in the world, has launched, with support from the Mozilla Foundation, a version of its site that uses only the HTML 5 'video' tag for video playback. This makes it the first large video sharing site to implement the feature and the move will allow users to view videos without the need for the Flash proprietary plugin. The announcement is a major breakthrough for the proposed HTML 5 standard and backers of open software and formats.

“Our users expect the best possible experience and we are excited to work with Mozilla, with whom we share the commitment to the continuous advancement of innovative Internet-related technologies,” said Sebastien Adgnot, lead developer on open video for Dailymotion.

HTML 5 is getting its fair share of attention lately and was the focus of the first day at the Google I/O Developers Conference last week. It is currently in draft form and its backers are pushing for its standardization though the latest versions of most major browsers, except for Internet Explorer, already offer full or partial support for it. HTML 5 will implement a number of features among which is the new 'video' tag that will allow sites to embed video using standard web technologies like CSS and JavaScript.

The Mozilla Foundation helped Dailymotion with its implementation of the video tag and the use of open formats like OGG and the Theora + Vorbis video and audio codecs. “Video is a vital part of the online experience. At Mozilla, we view the support of open, non-proprietary video standards as key to the overall health of the Web,” said Paul Kim, VP of Marketing, Mozilla. "Dailymotion’s strong support for open video helps move the Web forward."

Dailymotion’s current implementation is marked as 'pre beta' and there are some issues with quality and functionality. However, the developers have stated that this will change in the future and that the service will be at least on par with its Flash-based offering. The site is optimized for Firefox 3.5 beta but should work on other browsers too and Dailymotion has expressed its desire to collaborate with developers of both Webkit, the open-source rendering engine used in Safari and other browsers, and Opera.