The percentage of online video available in HTML5 format has grown 5X since January and more than 2X in the past 5 months, according to a report by web video cataloging service MeFeedia today. An estimated 54% of online video is now available in HTML5, generally in addition to availability in Adobe Flash.

What does that mean? It means iOS devices can play a whole lot of video without concern for Flash, it means that Flash's (alleged) memory problems can be minimized by deferring to HTML5 players and it may mean less industry dependence on Adobe's Flash publishing technologies.

HTML5 comes with all kinds of other advantages as well, from location support to advanced access to hardware support.

The MeFeedia survey incorporated analysis of video from more than 33,000 publishers, including Hulu, CBS & ABC, YouTube, Vimeo and DailyMotion. Adult video sites were not included, but given that the porn industry's technology tends to be as advanced as its politics tend to be retrograde - the percentage is probably even higher there.

The HTML5 video landscape is set to change even more, with startups like Sublime Video (our review) and (our review) making bold new entries into the field. Handroll, which is positioning itself as the WordPress of HTML5 video, recently built a simple Twitter client into its video player, for example.

For an in-depth technical comparison of Flash and HTML5 video performance, see Sarah Perez's article Does HTML5 Really Beat Flash? The Surprising Results of New Tests.