Finally, a theme-friendly and Waterfox-friendly addon so I can tolerate looking at my vertical tabs (which I must have). More than tolerate, I can hardly believe the vertical tab sidebar has finally just become part of a fully themed interface, and I can enjoy the increased productivity without the constant irritation of my tabs looking different from the rest of the interface.

Its smoother than other similar extension, also matches the theme used.
Only change i request is that to change the pinned tabs to icons.

Does what it says it does.

Needs more features though, such as scrolling through tabs, and auto hide of sidebar.

Looks best if you use css to hide the original tab bar.