Equivalent for firefox: https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/ https://addons.mozilla.org/en-US/firefox/addon/tree-style-ta... It suppo

Equivalent for firefox: https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/ https://addons.mozilla.org/en-US/firefox/addon/tree-style-ta... It supports grouping in the tab bar, or alongside in tree form. I find the integrated interface a bit better than the Chrome plugin above.