This is a plugin for FF, right? Is it this one? https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/ https://addons.mozilla.org/en-US/firefox/addon/

This is a plugin for FF, right? Is it this one? https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/ https://addons.mozilla.org/en-US/firefox/addon/tree-style-ta...