Browser Trends: Site-Specific Browsers
One thing that clearly differentiates web apps from their desktop counterparts is that the former run inside a tab or page in the web browser rather than in their own process. This has a number of drawbacks, several of which are elegantly set forth in the blog post announcing the launch of Mozilla Prism:
[ Author's note : I am a contributor to Prism.]
The reality is that the current generation of web apps are trying to shove a square peg into a round hole. The fact that they’ve managed to jam it in there as far as they have is a testament to the ingenuity of the software developers involved, but it’s not a particularly satisfying solution. One possibility would be to address this by adding more and more application-oriented features to the web browser. But why bother when many years and countless investment in R&D have led to modern operating systems like Windows and OS X that already give us everything we need?
There are a number of other reasons to prefer running a web app on the desktop rather than in the browser. By giving it its own operating system process, you isolate it from other applications. If it locks up or crashes, it doesn’t bring down the whole browser. You can use all the fancy docks and taskbars that the operating system provides to gain easy access to your applications. You can use tools like the Windows Task Manager to see how much memory and CPU power it is consuming. Once again, we could theoretically add these capabilities to existing web browsers, but the effort would be massive. Clearly the idea of fusing web apps with the desktop is a promising one.
The other main contender (besides Prism) in what have come to be known as site-specific browsers is Adobe AIR. Both products integrate a standalone browser engine (Gecko in the case of Mozilla and WebKit in the case of AIR). Both support SQLite so you can store application data locally. In other respects, however, the products are quite different.
The aim of Prism is to provide the aforementioned benefits to web developers with minimal effort on their part. In fact, you can run existing applications in Prism without any modification at all. In the future, developers will be able to write special configuration files that adapt the application to make it fit more comfortably into the desktop paradigm, adding things like a menu bar, drag-and-drop capabilities and popup notifications.
AIR is more about getting Flex, which lets developers write Flash applications using markup similar to HTML (and even more similar to Mozilla’s XUL), to run on the desktop. The product does support HTML as well, but the clear focus is on all-singing, all-dancing Flex-based user interfaces.
This distinction has already led to a minor skirmish between the principal actors. Mozilla’s Prism blog post claims that “unlike Adobe AIR and Microsoft Silverlight, we’re not building a proprietary platform to replace the web.” In the comments, Adobe’s Mike Chambers takes offense:
This is correct but somewhat disingenuous. It’s no coincidence that Adobe is showcasing an array of slick-looking Flex-based applications while Mozilla is touting its support for web stalwarts like Gmail, Facebook and Meebo. This doesn’t mean that one is bad and the other is good. Blind adherence to standards is not always the best way to drive innovation, and it’s hard to deny the visual appeal of Flash when compared with plain-jane HTML. Some canny moves on Adobe’s part might even lead to Flex becoming a standard in its own right.
There are other players entering this space, notably Fluid, which currently runs only on Mac OS 10.5 (Leopard). It’s also worth keeping an eye on Google Gears. Originally announced as a way to let web apps function without a live internet connection, it is being extended to support features like placing a shortcut to the application on the desktop. The implication is that Gears will evolve into a direct competitor to Prism, AIR and Fluid.
It’s extremely early days for all of these products. I wouldn’t recommend any of them for use by mainstream users, but if you’re technically minded enough to be reading this you’re definitely a good candidate to take a look at them in their current form. By the end of the year, I expect them to have matured considerably. Soon enough we won’t know how we got along without them.
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