After installing TenFourFox 10 and seeing it was an Extended Support Release, I decided to give myself a break from the constant upgrading and skipped the betas for 11, 12, and 13. Now 14 has come around, and as the internet keeps getting slower, I wanted to see if the new version offered any speed improvements.
However, if you're using Leopard, TenFourFox is not your only option. There have been a few newer browsers to join the fight and continue to support PowerPC:
The first is Leopard-Webkit. It's a build of the current Webkit sources, basically an updated Safari, and also supports h.264 video.
More recently there's AuroraFox (Firefox alpha channel), which is like a bleeding-edge version of TenFourFox. Though on their website they announced they'll reach "Judgment Day" with the release of version 17 since that's when Mozilla drops Leopard support.
Finally there's a new kid on the block, Seamonkey-PPC. Also Leopard-only, it's Mozilla's all-in-one browser suite with email, IRC, and more. It's goal "...is to maintain a working version of SeaMonkey for PPC based Macs." So check it out!
Some of you may also add Stainless to the list, but I'm not sure how active the project is (only one update in the last year).