The platypus of the Internet, from the Google Blog, has some details about the development. Or you can jump directly to the download page. Google Toolbar runs on Windows XP or 2000, Mac OS X and Red Hat Linux on both Firefox and IE.
In case you are curious, my favorite feature is the spell checker, which works in every form you are filling in. I use it when posting to this blog. It doesn’t make me perfect… but it helps. 😉
