“Mozilla has released a beta version of the next version of its Firefox browser with better memory management and significant speed improvements.
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“For many users with add-ons installed, this will significantly reduce Firefox’s memory consumption, without requiring upgrades to those add-ons,” he adds. “For those users, Firefox 15 is likely to be faster (sometimes drastically so) and less likely to crash, especially if they have multiple add-ons installed and/or keep Firefox running for a long time between restarts…”
Source: PC Advisor
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Firefox 15 Beta Tackles Memory Leaks