July 12, 2010, 1:34 PM — There's been lots written about the politics and process of the emerging HTML5 specification (see "What to expect from HTML5" and "How HTML5 will change the Web," as just two examples), but what working Web developers primarily want to know is: What can I do with HTML5, and when can I start using it? The good news is that there's a lot you can do with HTML5. The better news is that there's a lot that you can do with HTML5 today.
But first, one major caveat: You need to know your audience, though, of course, this is true whether or not you want to start using HTML5. If the majority of your site's visitors still use Internet Explorer 6, then you have no reason to rush. On the other hand, if your site is primarily for mobile browsers on iPhones and iPads, what are you waiting for? But if your site falls somewhere in the middle -- as most do -- here are some handy guidelines to ramping up to HTML5.
[ Read Neil McAllister's primer: "What you can expect from HTML5." | Find out InfoWorld's peace plan for ending the iPhone's HTML5-versus-Flash war. ]
What HTML5 features you can use now
Although the HTML5 specification is still a draft being worked on by a standard committee, significant portions are already deployed in Apple Safari, Google Chrome, Mozilla Firefox (with more to come in Firefox 4), and Opera -- and the forthcoming Microsoft IE9 is expected to adopt much of the draft HTML5 specification as well. The When Can I Use site is a great resource, providing detailed breakdowns of what each major browser supports for HTML5 and related emerging Web standards.
Browser Security Deep Dive
Another site, The HTML5 Test, displays compatibility scores, based on the number of supported HTML5 capabilities (out of 300), for each browser (you need to visit the site in each browser you want scored). As of June 12, 2010, the scores were:
* Apple Safari 5.0: 208
* Google Chrome 5.03: 197
* Microsoft IE7: 12
* Microsoft IE8: 27
* Mozilla Firefox 3.66: 139
* Opera 10.6: 159