HTML5

  HTML5 is the newest standard for HTML.  The combination of HTML5, CSS3, and JavaScript can create great things.  Last semester I took Graphical Application Development at FAU and (for the first time in the course) we were taught how to use HTML5's canvas to create graphical applications.  Since HTML5 is still new not all browsers support all of the new features...yet.

  To get you started with HTML5 check out these sites:

1.  w3schools - HTML5 Intro     W3schools has examples for you to try and a nice index if you are looking for a particular tag or attribute.
2. The New Boston Video Tutorials: HTML5  53 FREE HTML5 videos, broken up by subject.  Again, great for a newbie to learn and for the person who just needs a fresher for a particular topic.