[nine_k]

If you have so many tabs they don't fit on the top, just install Tree-Style Tabs extension. It puts tabs to the side panel, and organizes them as a tree.

If a killer, life-changing extension exists in Firefox which is not available on Chrome, this is that extension.

[olah_1]

I tried it for a while, but honestly, the UI for tree-style was ugly. If I'm going to look at and interact with something for hours on end, I can't have it be ugly.