Brendan Eich tells how to prevent JavaScript memory leaks
InfoWorld: Once leaks occur, what can be done to fix them?
Eich: Leaks require prevention in general, not reactive repair on a running system. If a developer's JavaScript code somehow misses a leak, it is not possible to automatically fix it [on the user's system after the fact]. If a developer did have a big table that carelessly stored references to all objects ever created, of course, you might treat it as a cache and purge old object references from it, but that's not really a leak, just a cache that needs careful tuning and reclamation policy implemented by your JavaScript.
Memory tools can also help. A memory profiler can show which objects are taking up the most memory. Then, a garbage-collection tracing tool can tell which program values are causing those objects to be kept.
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