[catnipman]

If it’s anything like previous major releases, the memory leaks will be twice as bad and it’ll hog 100% of CPU as it reaches 2 gigabytes memory usage after browsing for 15 minutes.

[Robert A Cook PE]

So how do you prevent the memory leaks?

[steve86]

the memory leaks will be twice as bad and it’ll hog 100% of CPU as it reaches 2 gigabytes memory usage after browsing for 15 minutes.

FF has no such memory leaks and hasn't had for several major versions. Add(s)-on do.

I can run FF 4.01 and 5.0 on an old laptop with 192 MB memory and it's fine. Generally around 128 MB in use + caching, buffering. Very little use of the swap file.