<a href="https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;bartab-plus&#x2F;" rel="nofollow">https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;bartab-plus&#x2F;</a> does the same thing (actually a little better in the implementation) on Firefox.  Once you install, go into config for it and set how long a tab may be idle before it auto-unloads.  Unloaded tabs are shown slightly dimmed in the tab bar.  You can also right click tabs (such as gmail &#x2F; youtube &#x2F; etc) and force them to always stay loaded, so your email &#x2F; music streaming &#x2F; etc aren&#x27;t impacted.<p>Combo it with <a href="https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;tab-groups-panorama&#x2F;" rel="nofollow">https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;tab-groups-pa...</a> that lets you organize your tabs into groups and you can have hundreds of well organized tabs without using much memory at all.