HTML5: It's one of those exciting buzzwords that is supposed to bring the mobile word closer together.
Unfortunately for Facebook, they realized that hedging their bets on an emerging technology turned out to be a bad risk to take. In this Forbes article, J.J. Colao details how HTML5, meant as a solution to provide content to myriad operating systems and many more hardware configurations, turned into a nightmare. The article quotes the CEO of a mobile development firm as saying HTML5 development is "10 times as hard" as creating native apps.
Harder for the developer, and as it turned out, a pain for the user, who ultimately suffered from poor performance.
Nevertheless, Colao concludes that Facebook's invedtment in HTML5 will pay off for the time being as most users still access the platform via a Web browser.