[swenn]

An alternative vertical tab bar I discovered some time ago is Tab Center (https://testpilot.firefox.com/experiments/tab-center). Although still a little buggy, I switched over from Tree Style Tab. It feels better IMO and I really didn't care about the "tree style" of TST, I just felt the need for a vertical tab bar.

[KingMob]

Wow, I just tried it, and it's the tab interface I always wanted. More vertical space for reading web pages, and wider tabs to read the tab titles more easily. Why isn't this the default yet?

[baby]

A lot of people are wondering why this is not the default. If you like this you should try Tree Style Tab ;)

[baby]

I tried it and unfortunately no nested tabs :/

[lomnakkus]

I must admit I don't really understand the use case here. (Vertical, obviously, because you can exploit the wide screens we "all" have.) Can you explain why you want nested tabs?