SenseOfHumor writes "The Firefox memory leak is not a bug. It's a feature! The 'feature' is how the pages are cached in a tabbed environment." From the article: "To improve performance when navigating (studies show that 39% of all page navigations are renavigations to pages visited less than 10 pages ago, usually using the back button), Firefox 1.5 implements a Back-Forward cache that retains the rendered document for the last five session history entries for each tab. This is a lot of data. If you have a lot of tabs, Firefox's memory usage can climb dramatically. It's a trade-off. What you get out of it is faster performance as you navigate the web."