Firefox 3.6.4
[Update: Sorry for the confusion, but the Mac version of Firefox does not have the feature that protects against crashes in plug-ins. -Adam]
Mozilla’s Firefox 3.6.4 addresses a handful of security vulnerabilities and improves stability when plug-ins crash. Most notably, if the Flash, QuickTime, or Silverlight plug-ins crash, they won’t take down Firefox itself. (Just reload the page to restart the plug-in.) The security vulnerabilities could result in arbitrary code execution, as usual, so it’s nice to seem them fixed. Release notes are available. (Free, 17.6 MB)