Number 1 add-on of any add-on that has ever existed:
A+ | 10/10 |

Must have. Cannot use a browser without it. No other add-on has the same feature. Thanks a lot!

The reason why I am still using firefox and love it very much. This is must have addon, that makes life easier and more organized.

作ってみてわかったけど、
かなり細かいところまで、お手製で作りこまれている。すごい。

Great extension!
The only thing that could be improved is a default smaller tab height like before the WebExtensions version. But it can be changed with a code snippet found on the extension wiki.

Came to it as a replacement for Tab Groups when Firefox Quantum stopped supporting that one. Was great while it worked, but now it just shows the loading icon forever; both on Linux and Windows. EDIT: After update works perfectly again

Works perfectly. Thank you.

I was worried that after quantum that treestyletab will be dead. However, the dev did a great job finding a way around it!

Sadly, currently broken.
It guzzles memory and CPU time like nothing else I've ever used and really slows down the browsing experience. This addon should *not* be going to 80% CPU usage and adding 2-4GB of RAM usage just because I opened a single tab.

I hope it gets fixed soon.

edit: My mistake. The real cause of the problem was one of the settings in the Tab Session Manager.
5/5 for Tree Style Tab itself.

A must-have add-on.

So glad to see this back in Firefox Quantum

It totally changed my internet browsing experience! I don't need to search where was that tab. I know where I got there from (on which page I clicked a link when new tab was opened). I know which crappy site opened a new tab without my permission. I can close whole "topic" of tabs. It is like the already existing tab-groups but evolved onto a higher level and on steroids. Problems? There are some: firefox memory limits and the fact that my browser often has 1k+ tabs opened at a time. Over a thousand - and it still works :D Don't try this on chrome or safari. Not even mentioning IE. TreeStyleTab is just great. And user experience is nice as well (Piro provided links on how to deal with UI restrictions - could be more permanent/readable but it is there.... to solve issues that he couldn't do on his own).

A great add-on. May I propose an idea? ) It would be great to have, as an option, side-tabs colored depending on tab domain.

My favorite addon! Though currently when I reopen my second window, it usually forgets the tab tree structure (un-indents all tabs). Otherwise it's perfect.

Vastly improved my tabbing experience. A must for everybody!