Firefox is famous for hogging up memory. If you are using 256 Mb RAM or lesser then your system hangs if you open a lot of tabs at once. Firefox does a lot of tasks internally like scanning for viruses, checking for updates of themes and addons and such, for which it needs RAM and that is the reason it hogs up so much memory.
There is no automated way in Firefox to notify these processes to free up RAM being used in such state. This is where RAMBack comes in picture. Once you install RAMBack, Firefox will automatically send notifications to all the processes that are hindering the performance of Firefox.
RAMBack is still in Beta stage, so do not expect it work wonders. People who have PC’s with 256 Mb RAM or lesser have seen significant improvement in the performance for memory usage by Firefox.
[ Download RAMBack ]
(Related post : How to restrict firefox from eating up RAM )