This the one, the only 10-star add-on.
5 stars for the value of its mission
5 stars for execution
Firefox has some work to catch up to where it was before, but it can still handle this add-on quite well. Visual, collapsible tab tree just makes the browsing experience so much more sensible.
I'm looking forward to seeing the weird old tab bar disappear again, but that's a problem with WE not with this add-on.
I can hardly remember a time I was this happy with a browser feature since the invention of the DOM inspector.

No good under webextensions

most valuable firefox extension, and in fact the only reason to use firefox. thank you!!!

yo! I second "Can't live without it"
Thanks a LOT for this awesome extension.
Several years ago (about 6 i think), the sudden inspiration crossed my mind, that tabs should not be listed horizontally, and after some longer research at that point in time (treestyletab was lesser known), i found this and was happy EVER AFTER.
It's pretty incredible that the devs made this working with firefox Quantum out of the box, I can't believe the effort.
I just wanna say: Thank you!
And you don't even want Donations, tears in my eyes, much love :)

I like it a lot, but I'd like to be able to change the background and text colors and weights of the tabs themselves in Firefox 57/linux. Some of the .css tweaks work, some work in strange ways, and some don't work at all. It was way better before FF57.

TST is the reason I've never even considered switching to using another browser. Works perfectly on FF57. Thank you so much for all your hard work!

Thanks for this add on, it's realy helpfully for user who use a lot of tabs in a session.

I really miss 2 things that wass very usefull, the auto hide, and the transparency without rezize the webpage area.

I don't know if it's posible cus the api limits.

Thank you for this very useful addon, cannot use browser without it.

Splendid job on converting to Firefox Quantum. With the changes to chrome.css from the wiki, it looks great!

Так изуродовать прекрасное дополнение ... Это надо было приложить массу усилий.

ok

Nope. This will not work until the horizontal tabs can be eliminated. It is way too odd to have two tabs areas showing.

Tree-style tabs are more compact and orderly than organizing tabs through the normal tabs bar. This extension has a few bugs in it, but it's still indispensable to saving time on the internet! Thank you, Piro. :)