Ubiquity is a Firefox extension that aims to empower users and allow them to tell the browser what they want to do. It allows everyone, from common users to developers, to create their own mashups depending on the need at hand.
Ubiquity isn’t just a fantasy or a concept idea, it is already in the early stages of being developed. The current version is 0.1 and it can already email your GMail contacts, look up things on Wikipedia, show you the weather, define terms, get maps, and so much more.
You can download Ubiquity from the announcement page. This will be an XPI file, which you just open with Firefox. Once installed, you will be taken to the about:ubiquity page. I would suggest from here, taking a look at the User Tutorial. This will help you get to know a few of the commands, but there are so many more things that you can do. To see everything that Ubiquity can currently do, you can visit the command page, which lists and describes all current commands. (This can only be viewed in Firefox.)
Ubiquity is kind of restricted right now. It’s not completely functional using Linux (but Mac and Windows users are good to go.) The email commands only work with GMail right now. And of course there are probably bugs that need to be worked out in some of the commands. But if you are developer, you can write commands for Ubiquity. Read the author tutorial here.
Of course, there is tons of information and links for support and discussion on the announcement page. I may be a nerd, but I think this is really exciting! I’m happy to be part of the early stages and to have the opportunity to shape the future of Ubiquity and see the evolution of it.
Update – 09/13/08:
Here is “The Ultimate List of Custom Ubiquity Verbs” from ReadWriteWeb