Richard McManus, from Read/Write Web, has posted an excellent point/counter-point article debating which is better: online desktop applications or offline web applications.

First off, the two sound remarkably similar and at first glance one might ask: what is the difference? The differences are significant here - with the most apparent being that a desktop application (whether it be online or offline) must be downloaded and installed first and a web application is merely accessed via the browser.

I am going to side with online desktop applications in this debate - primarily because of the 90% of the computing market that has no idea what Web 2.0 is or it’s definition. On my grandfather’s computer, if it’s not on the desktop it doesn’t exist. Of course, I could easily create a shortcut to the web application but that adds in another problem my grandpa must attempt to solve - “why does this look just like my web browser, I’m not online?”

From a usability standpoint I feel desktop applications are still the comfort zone for most of the market. I have attempted to explain to my wife why this website can do exactly what she wants but she always comes back with “why?” For her, she wants the icon to click, whether it be on the desktop or in the taskbar.

On the technical side, I once again side with desktop applications as they have the ability to access the underlying filesystem. Web applications are great due to being inherently cross-platform (although the browser wars are really starting to mess that up) but there are many tasks which simply need access to the operating system and that’s something a browser simply can not do. Also, a desktop application receives its own dedicated chunk of memory to use and abuse; whereas web applications only get what the browser allows them (many productivity suites limit the amount of data one can process at a time, usually to 512kb).

Firefox 3 might change my opinion on this - as there is a lot of innovative ideas being tossed around as to how to handle offline web applications. But, for now - desktop applications still take the cake due to their familiarity with the user base and the power they inherent from residing on the user’s machine.