It’s no secret that fragmentation — which has long plagued the mobile industry — is getting worse by the day.

Symbian is still the largest mobile operating system, but claims only 43 percent of the market, according to new figures from Gartner. Apple’s iPhone OS and Google’s Android are steadily closing ground, while meanwhile, BlackBerry somehow continues to gain momentum and Microsoft’s Windows Phone 7 and Samsung’s Bada will come to market later this year. To further complicate matters, a host of app storefronts exist (or are being built out) by software developers, handset manufacturers and carriers. So consumers are increasingly confused, and app developers must figure out which platforms to build upon and which storefronts to use for distributing their apps.

Many industry onlookers have pointed to hope on the horizon in the form of WebKit-based mobile browsers that could eventually reunite the splintered world of mobile data by giving developers a single platform on which to build applications. But while WebKit may eventually become an effective tool for developers as we move toward web-based apps, it won’t be the panacea some have predicted.

WebKit’s traction is nothing new, of course. The open-source layout engine is at the heart of browsers used in Android, iPhone OS, Symbian and webOS. Even BlackBerry has joined the bandwagon, which leaves Opera and Firefox as the only two browser developers of note to eschew WebKit. Once RIM deploys its new browser, roughly 85 percent of new smartphones will ship with WebKit-based browsers, according to Jason Grigsby. And WebKit has gotten even more media lately, after Steve Jobs publicly professed his adoration for the technology.

There’s a lot to like about WebKit beyond its dominant presence in mobile. The technology supports HTML5, which will help lessen the need for proprietary technologies such as Adobe’s Flash and Microsoft’s Silverlight. That’s a huge plus in mobile, where users with iPhones or iPads can’t fully access the Internet thanks to Jobs’ petty catfight with Adobe. WebKit’s small footprint and high performance make it ideal for mobile, where devices are smaller and less powerful than other platforms. And developers say it’s easier to code for than other mobile browser engines.

So WebKit has the potential to be a huge force in moving mobile data beyond native apps and toward a standardized world of web-based apps where developers can address huge mobile audiences with a single build and consumers aren’t constrained by the kind of hardware they carry.

The world of WebKit isn’t quite as unified as it may appear, however. That’s because there is no single WebKit standard. Companies and developers are free to create and distribute their own individual WebKit browsers, and they alone are responsible for creating and pushing out updates, making them highly susceptible to fragmentation. Indeed, one techie last year tested 19 WebKit-based browsers for compatibility and found that no two were exactly the same, and that regressions were “fairly common” — versions of some iPhone and Android browsers, for instance, dropped support for features that preceding versions had supported.

WebKit may eventually serve as a kind of baseline platform for developers of web-based apps, enabling them to create foundations of their apps then tweak them for each WebKit-enabled browser. But it won’t provide the foundation for a “write once, run anywhere” environment that developers have long dreamt of, and it won’t do much to simplify things for consumers who just want apps to work across devices and networks. As Richard Wong of Accel Partners wrote a few months ago, “In mobile, fragmentation is forever.” So developers hoping for a single unifying force in mobile may as well be waiting for Godot.

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