MultiZilla
Mozilla just hit critical mass. I had read a fair bit about the XUL architecture and Gecko rendering engine but I didn’t really get it until recently. David Boswell’s article, Let One Hundred Browsers Bloom on O’Reilly Network is a good introduction to the myriad possibilites that are now unleashed. 101 things that the Mozilla browser can do that IE cannot on XulPlanet also is a good overview of what it’s all about. Ars Technica ran a good review when Mozilla 1.0 was released, although it’s now slightly dated.
One of my favorite applications (or “plug-ins”?) that takes advantage of Mozilla’s extensibility is MultiZilla, which does all sorts of crazy things with tabbed browsing. The webpage describes all this fairly well; my favorite extension is one where you can take a whole set of tabs and “bookmark” them as a “groupmark”, and then later open that groupmark and get all of those tabs together again. I do this to read the news—I have seven or eight news sites I like to read first thing every day, so I’ve groupmarked them, then I go through each one, opening up new tabs (by middle-button-clicking) on articles I’m interested in. As I finish going through everything in a particular tab, I close it with a Mouse gesture and move on to the next one; essentially going left-to-right, new articles leapfrogging to the end.
I suspect most people don’t necessarily want or need to use their web browsers this way, but for some it opens up new ways of interacting with the web. I believe eventually this will lead to new ways of thinking about the whole technology. We’re now at a point, finally, where the web browser can be a platform upon which castles are built. If nothing else, that’s a good thing for competition.