The trouble begins when you have something like 30-40 tabs open, I think. Firefox is among the first programs I open after logging in, and I usually leave it r

The trouble begins when you have something like 30-40 tabs open, I think. Firefox is among the first programs I open after logging in, and I usually leave it running until I either shutdown/reboot or a browser update makes me restart it. And I tend to only reboot my computers (both at home and at work) when system updates make it necessary. Often I will open a page and then just leave the tab open for "later" (which might be hours or days later). It's not uncommon for Firefox to grow to 1-1.5 GB in size. Personally, I consider that an acceptable tradeoff, given its usefulness, but it is a rather heavyweight program. (On lower-end machines I prefer either dillo or w3m. Pages with layouts that can be even remotely considered "fancy" will look kind of strange in dillo, but it is incredibly fast, and I have never seen it use more than 150MB of RAM.)