Windows/Mac/Linux: Firefox Tab Candy is a new tab management feature for Firefox that organises tabs into groups to help you keep your tabs grouped by task. Not only does it offer incredibly handy features, but it looks beautiful.
Watch the video above, by Mozilla's excellent interface designer Aza Raskin, for a quick overview. Tab Candy isn't currently available as an extension, but Mozilla is offering an alpha download of Firefox that includes Tab Candy by default (all platforms). We wouldn't recommend anyone jump to it as their main browser, but if you're eager to try it out and are comfortable with alpha software, it's worth a look.
(Click the image above for a closer look.)
We've just started playing with Tab Candy, but so far we're loving it. If you give it a go, let's hear what you think in the comments.
Firefox with Tab Candy Alpha Downloads [Mozilla FTP]
Tab Candy: Making Firefox Tabs Sweet [Aza on Design]