In fact, RIM is now expanding and refining its HTML5 support, which began in 2010 with BlackBerry OS 6 after RIM bought Torch Mobile, a mobile browser company focused on the widely used Webkit browser platform. Since then, the BlackBerry browser has been repeatedly upgraded with more HTML 5 support, along with BlackBerry OS 7, and the PlayBook OS 1.0 and in February, . PlayBook OS is the QNX-based precursor to BB10. RIM's mobile browser for BlackBerry OS 7 current ranks in the middle of the pack at but the in-development BB10 browser outstrips all of them except for one, also in development.

The latest HTML5 additions in PlayBook OS 2.0 are no automatic assurance of high performing, well-behaved HTML5 features. One example is the inclusion of the Web Notifications API, previously only found on Firefox for Google's Chrome OS. This is a "killer" feature that enables "Web apps to communicate with the user anytime" via a "notification in the operating system from a webpage...," writes Max Firtman, a development trainer and author of, among others, "Programming the Mobile Web" from O'Reilly Books, in a February 2012 . 

But on the Tablet 2.0 release, "it seems to be incomplete," Firtman wrote. "I was able to show a background notification but I could only catch the click event when the user closes the notification with the little "x" icon, not when clicking on the message. Even clicking on the notification's message doesn't do anything. It doesn't open the browser again, it doesn't open the URL [that] I gave when creating the notification and it doesn't trigger any event."

Yet he also wrote that "This new version is again surprising me," with the range of HTML5 firsts it offers. " It's the first mobile browser with remote Web Inspector for debugging over the LAN (instead of USB as in the Chrome browser for Android), an HTML5 File API, 3D transformations, Scalable Vector Graphics (SVG) fonts, and Browser History API, according to Firtman.

BlackBerry 10 "will be great for Web developers," promises RIM's Stanley.