Mark Zuckerberg doesn't know how to use HTML5

Open ... and Shut Even as Facebook dumps HTML5 to embrace native app development, calling its early enthusiasm for HTML5 its "biggest mistake," Sencha, a leading provider of open-source web application frameworks and tools, has not only demonstrated real-world readiness of HTML5, but has actually built a Facebook app that performs better than Facebook's native apps.

As Sencha explains on its blog, the problems with Facebook’s misadventures with HTML5 have more to do with Facebook than with HTML5: