Ubuntu and HTML5 (unrelated)
Two things. First: I have upgraded from Hardy Heron to Lucid Lynx and it all works very nicely, except a minor bug that has something to do with visual effects, the bonobo server and the screensaver...I'm not using a screen saver and the problem is gone. I upgraded, probably a new install from the CD would solve the problem completely, but I don't mind, it's fine as it is.
The second thing: I thought my web site was written in XHTML 1.0 Strict (it validates as such) but I found out that, since I'm serving pages with a MIME type of text/html, I'm not really using XHTML (HTML5)...
Read this: Dive Into HTML5