A couple of days ago a friend asked me this question can i use HTML5?. Lets say you want to develop a web shop to sell certain items online, Will you use HTML5, just to make it modern? well the answer according to me is No in most of the cases and yes in some. Well it depends on what is your target audience and what versions of Browsers do they use. Well HTML5 wont work on a machine using say IE6 and will screw up totally.
If you visit the W3C page for HTML5 here http://www.w3.org/TR/html5/. You will see a red strip at the bottom giving you a good piece of advice.
Yes as it says HTML5 is still a work in progress and excepted to be better and stable around 2014-2015. here is also a standards page http://www.whatwg.org/specs/web-apps/current-work/multipage/ if you have a look at the Draft update dates… it is updated quite recent.
Here is a nice example how the browsers have developed during the years 2008 to 2011 http://html5readiness.com/.
Here is another great website http://caniuse.com/ showing you what different browsers support what all features and what all you should or can use. Here is the link for HTML5 http://caniuse.com/#cats=HTML5 .
Here is another for mobile browsers http://mobilehtml5.org/.
And try this HTML5 test, go to this link http://html5test.com/. So did you get a 100% score?