Awesome

Tab Groups

This add-on will not receive any more updates!

It will cease working by next November with Firefox 57. <a href="http://fasezero.com/lastnotice.html">Click here</a> for more info. Feel free to fork and use however you like.

AMO url: https://addons.mozilla.org/firefox/addon/tab-groups-panorama/

Babelzilla page: https://www.babelzilla.org/index.php?option=com_wts&Itemid=0&type=show&extension=5749