firefox - world's worst browser by now. its time to look after a different one.
thats one thing that they was still unable to implement multiprocessed/multithreaded browsing in the stable version, even 10 years after the cpu-s having multiple real/virtual cores, so you have to wait 2 minute for facebook to render, if you open 10-20 tabs with your notifications.
but they not even attempted to fix any of the bugs i reported to them, some exist since 4 years by now, and they dont give a shit.
for example, to display a few simple web-page, it needs 1 gbyte of RAM. if you save a lot of images, and run the software for a while, the save popups forget to appear, or they just cant download any more. if you have lot bookmarks, it takes minutes to load it by its sql-javascripted interface. if it have chance, it dumps 1-2 mbyte to the disk per minute, your pendrive will be happyly die after days, if you have the portable version. even if you disable all cache saving, of course, without that, it can be 20-30 mbyte per minute, rofl.
this browser is purely pathetic in every mentionable ways. this program is the example of a communist state in software form, the example when the productivity of a group is smaller than the productivity of the smallest element of it.
however, all opensource software is like this.