Prism is an application that lets users split web applications out of their browser and run them directly on their desktop.
I've been telling my friends about one of my favorite new apps which just came out of private beta, Mailplane. It's one of the few pieces of shareware I've actually bought. It's not that it's that amazingly innovative. It basically is just a standalone web browser using Safari's Web Kit that's sole purpose is to run gmail.
It brings gmail out of the web browser and back into the Mac OSX interface.
It has some custom configurations, but that's basically what it does and that's really all it needs to do.