DHTML Leaks Like a Sieve

the design of both major browsers (Internet Explorer and Mozilla) leaks memory necessarily
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Let's take a moment to think about that "necessarily" part. What I mean by this is that these browsers are not poorly implemented (I'm not going to pass judgment on that), but rather that their design leads inexorably to memory leaks.
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And don't feel tempted to think "It's probably not that bad; I'll just ignore it" -- neither Internet Explorer nor Mozilla free these objects even after a page is unloaded, so the browser will just blow more and more memory. In fact, I first noticed this problem in my own work when I saw IE blowing around 150 megabytes of memory!

Article also provides some advice on alleviating the problem.

(via QuirksMode)