...is the code name for Firefox 3.1. Been using it for quite some time, but it's only in the latest versions that it has the new name. I'm on beta3, and believe it or not, it is actually noticeably faster than the beta2 version. However, it is having some problems identifying itself. The Firefox welcome page begs me to upgrade to a newer version, even though it has a build date of today, and the upgrade link is a recursive pointer to the same beta3 that trips the page in the first place. Yahoo had a little fit too, insisting that I needed a newer browser to use the features of its main page - which of course is not true.
3.2 early alphas are also available, but I figure it's best not to get too far ahead.
Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090125 Shiretoko/3.1b3pre