DragonHawk writes "Mozilla Firefox 3.6.4 went to general release today. The big new feature in this release is out-of-process plugins (OOPP). This means things like Flash, Java, QuickTime, etc., all run in separate processes, so when Flash decides to crash, it won't take your browser out with it. If Flash starts consuming all the CPU it can find, you can kill it without nuking your browser session. I've been using this feature since it was in the 'nightly build' stage, and it was still more stable than 3.6.3, just because Flash was isolated."
And reader Trailrunner7 supplies another compelling reason to download 3.6.4: "Security researcher Michal Zalewski has identified a problem with the way Firefox handles links that are opened in a new browser window or tab, enabling attackers to inject arbitrary code into the new window or tab while still keeping a deceptive URL in the browser's address bar. The vulnerability, which Mozilla has fixed in version 3.6.4, has the effect of tricking users into thinking that they're visiting a legitimate site while instead sending arbitrary attacker-controlled code to their browsers."