Problem with FireFox Quantum.
It is not possible to display two panels, left and right at the same time.
In the previous version firefox (56.*) it was possible to display bookmarks in the left panel and on the right opened tabs at the same time.
Now, in FireFox Quantum, only one panel is available, left or right at one time. Open tabs are displayed at the top and do not depend on whether the Tree tab is enabled or not.

リリースから結構経ってだいぶ良くなっててうれしい
以下気になっているところ
1. "新しいタブでリンクを開く"アドオンと､"Glitter Drag"アドオンを使っていて､新しいタブを開いた時､1つ下の階層の末尾に子タブが追加されてくれない
1つ下の階層の1番上に追加されてしまう
TreeTabsではちゃんと末尾に追加されるので､多分TreeStyleTabのほうに原因があると思う

2. Ctrl+Tで新しいタブを作る時､今開いているタブの子タブとして開けない
全てのタブの一番下に開かれてしまう

3. セカンドサーチで検索した時､今開いているタブの子タブとして開けない
タブ構造の最末尾に開かれてしまう
要するに俺は全ての結果を今開いているタブの新しい子タブとして開きたい
TreeStyleTabの性格的に筋違いではないと思うしできるようにして欲しい

4. タブが太い
56までの細さのほうが好きです
タブの太さを調節できるようにして欲しい

I absolutely rely on this extension - but lately on Windows it just shows the loading icon forever and never loads the tab tree, so I've had to knock it down to one star. (My Mac version still works, a little slowly.) Normally this extension's an easy 5/5 for me, with the new bizarre decision to place the tabs on the title bar making Firefox absolutely unusable.

It does not seem to work because it only shows open tabs--it does not show how I got to the latest site. The sidebar shows all of the current tabs but it doesn't show any children if I click on a link on the page represented by the tab. Can't figure out how to get it to work.

exactly what I need!! since years indispensable for any desktop web junkie who wants to use more than 10 tabs...

It's awesome. My wide-screen monitor is finally useful.

Very customiziable and does exactly what I been looking for.

Words cannot express how awesome this plugin is (and has always been). I have been a TST user for many many years and it is the first extension I install on FF on any computer I use and is also the only extension for me that counts as a must have. It makes my browsing experience so much more richer and I am eternally grateful to the author for his continued hard work on this extensions (especially to port it to the latest FF which was no small undertaking).

Good looking and very useful, but quite the performance hog.
Its own Firefox process runs all the time over 20% CPU (why all the time???), at session restore needs like one minute to redraw... I keep like 300 tabs in 4 windows, so this looks like a limit. Yes I can kill its process then the tree disappears and the machine is fast again, but that's not the point.

Works great, helps me keep my tabs organized better than any other tab extension out there.

If you are trying to remove the tabs from the top, please try the code at my gist: https://gist.github.com/SgtPooki/3e4143de258563653fc4082b2ac0f886

Install this extension now.
Press F1 to toggle the tab sidebar - tabs are a "child" of the tab you opened a tab from. This means your tabs are auto-categorised and you can see the "history" of how you got to a page at a glance.

I was concerned this would no longer be available for FF57, but the author has re-written the extension, leaving it better than ever.

It fits new firefox design :D

Very useful. However too few options. I wish there's a way to one-click sort and group all tabs under same URL.

Great addon, but I wish it had some improvements. The trees are really handy, but when closing a tab, the tab I get moved to sometimes isn't the one right next to what I had open. And I rally wish this allowed you to tag your tabs after already having them open. Having to tag, duplicate, and close is a rather bothersome.