For starters, HTML5 is a new tag that can be used to embed and display audio – video content on webpages without any need for separate plugin support like Adobe Flash. As a result, you can watch Youtube, DailyMotion videos embedded with HTML5 tag without Flash player installed on the computer. Newer version of Firefox 3.5 comes loaded with HTML5 tag support.
Now you can watch HTML5 videos in full screen using new Firefox addon “full screen video”. After the install, it adds a new menu option “fullscreen”. While video is playing, just right click and then click on fullscreen option to view HTML5 video in full screen mode. Download Full screen video firefox addon, very handy to view HTML5 video in full screen mode. Since HTML5 is evolving, don’t expect super smooth results – nice beginning though!