Both Web 2.0 and Software-as-a-Service (SaaS) almost always depend up on the browser as a common denominator. It is with the web browser that web-based applications are accessed and run, yet the browser model is rapidly reaching its limitations.

Adobe thinks it has the answer and so now does Mozilla.

A year ago, most web developers had to think about Firefox, Internet Explorer, Safari, Opera and perhaps WAP for mobile devices and widget development for one of yet more platforms. Today the horizon is changing and web developers are afforded more opportunity and possibly with that more complexity, through offline development.

Browser extensions now exist that allow for the creation of offline web applications with Dojo Offline, Google Gears, Firefox 3, and other options on the market, pioneering the way and making it possible to take your web application with you on an aeroplane or an underground train.

The drive to make these offline applications desktop applications has also been thrown into the mix, with examples coming from Apple with WebKit Cocoa bindings, Adobe with AIR and Microsoft with Silverlight. Now it is the turn of Mozilla to enter the foray with a project called Prism.

Prism is part of an experiment by Mozilla designed to “bridge the divide in the user experience between web applications and desktop applications“. Essentially, Prism will allow you to create a desktop-like application out of individual websites. These site-specific applications are a growing trend and a trend heavily marketed by, not only Adobe, but now Mozilla, as ‘the future’.

While traditionally users have interacted mostly with desktop applications, more and more of them are using Web applications. But the latter often fit awkwardly into the document-centric interface of Web browsers.

In its current form, Prism doesn’t have the ability to function as a desktop application without access to the Internet, but Mozilla says it is “working to increase the capabilities of those apps by adding functionality to the Web itself, such as providing support for offline data storage and access to 3D graphics hardware.”

Instead of needing to run a browser to, for example, access Google Calendar, a simple icon can be clicked on the desktop. The icon will launch the Google Calendar application inside a Prism window, without any of the additional web browser bloat. This can have its benefits, especially when designing workflows and securing applications as the developer’s pain, the back button and address bar, are removed from the equation.

Although Mozilla may be excited about the concepts behind Prism, and Adobe about AIR not everyone shares the same enthusiasm, or has the working habits that require such an application-based approach. For some, the advantage of web applications is that they inherently aren’t desktop applications and everything can be handled in a single application almost anywhere on the planet, assuming a computer with a browser and web connection. However, Prism, AIR and Silverlight could end up offering the best of both worlds.