Site-specific browsers may seem counterintuitive at first sight: The whole point of modern browsers is that you can do so much without switching apps–or even windows, if you’ve got tabs enabled on your browser. Why on earth would you want to firewall off browsers for specific sites?
But consider this not-atypical usage case: My laptop at home always has three windows open: Gmail, my .edu e-mail, and my calendar. Over a night, I might also check PbWorks, upload a video to YouTube and write a blog post about it, upload and edit photos in Flickr, and work with Google Docs. Click on a few links in Twitter or NetNewsWire, and the number of open windows or tabs can escalate pretty quickly. If the browser crashes, then it takes everything down with it, which is irritating. Plus, if you have several windows open, they all look alike–that is, they all look like Firefox or Safari windows or whatever.
Site-specific browsers put a halt to all that. A site-specific browser (SSB) makes a special version of an application that’s dedicated to a specific site. This isn’t a different window. It’s actually a standalone instantiation of the browser, so that anything that happens in another open instance doesn’t impact this one. You launch it the same way you launch any other application–which means it can have its own icon!–and you can trick out the browser as needed to optimize that particular site. And when when you click on a link, the SSB is smart enough to open the link in your regular browser, not the specialized SSB version.
As a Mac owner, I use Fluid, which is free and offers tighter Leopard/Snow Leopard integration than the cross-platform solutions such as Mozilla’s Prism. (There’s even an awesome Flickr group of icons to use with all the different SSBs you create.) Anymore, then, I have an SSB dedicated to Gmail, one to my calendar, and one to Brizzly. (Brizzly doesn’t play great with Fluid, but it works well enough.) Here’s what it looks like in action (example from the Fluid home page):
In short, if you depend on your browser to get your work done, then you should consider a site-specific browser. You will probably see a slight performance uptick, and you’ll almost certainly find your browser less crashy.
(Some other time we’ll cover single-serving sites, which is a whole different, and much funnier, concept.)