Changes

# Smarter use of memory: , e.g. more space-efficient data structures.# Avoiding leaks of all kinds (. This includes both true leaks (where memory is lost forever) and "quasi-leaks" (where memory is not lost but held on for too long, e.g. due to infrequent garbage collection).

The latter is Leaks are generally more important, as leaks they are more likely to lead to horrible performance.

Primary goal: to minimize bad performance (primarily paging) caused by poor memory usage. That's hard to track, though. A more trackable goal: get the number of leaks reported against a single version of Firefox down to zero, and keep it there. This will require some judgment on what constitutes a valid leak report, but that's no different to security bug reports, for example.