Something has to be done to firefox

Someone has to design a garbage collector for Firefox, Its eating every byte I have! All the other browsers are under the same conditions.. 1/2hr of browsing each. Opera lowest as you can see.. and VirtualDub running encoding a RAW AVI didnt need any memory. It doesn't matter to me but on slower systems its a pain. People of the Moz! fix the damn leaks! please!