Firefox has tab grouping (since version 4, meh). It's awesome and everything is accessible from keyboard.
No need to use tree style tab bar. Well, now I don't need a tab bar at all.
Ctrl+Shift+E. Hope that helps.
Happy surfing!

Hello.
Thanks to MichishigeKaito I paid a little bit more attention to zenburn colorchemes than I used to ( Read more... )