This add-on is, for now, no longer being maintained. Please read the FAQ at https://github.com/philikon/BarTab/wiki/FAQ for any further questions.
So you keep open tabs like libraries keep books... Aren't you afraid Firefox will consume all your memory? Don't you fear browser restarts because it takes so long to reload all your tabs?
Well, you shouldn't! Because now you can put all the tabs you don't need on your bar tab, and only pay for the load when you actually want to visit them.
BarTab can intercept when tabs are loaded in the background or restored after a browser restart and will only load the content when the tab is actually visited. It also allows you to free memory by unloading already loaded tabs, either manually or automatically.
This extension is under the same license as Firefox itself, the Mozilla Public License Version 1.1.