From mozilla 0.9.3 release notes:
* Continued stability improvements with 16 top crash bugs fixed since 0.9.2. These bugs were fixed thanks to data generated by users running talkback builds.
* The Subscribe dialog now lets you search for all newsgroups containing a string when subscribing to newsgroups.
* The Modern theme has several changes to icons and sidebar tabs.
* Proxy Auto-Config has been implemented on the Macintosh.
* There is a new preference for choosing between Windows and Linux scrollbar behaviour when the mouse strays off the scrollbar when you're in the process of scrolling. (Bug 90985)
* Chatzilla is now localizable.
* Personal Security Manager 2.0 with improved performance and new UI.
* MailNews front end has been overhauled with a huge performance
improvement.
* Browser and Mail now utilize a new cache, and new viewmanager
for improved performance and correctness.
* Image rendering library was rewritten from scratch for increased
preformance.
See the release notes below for detail:
http://www.mozilla.org/releases/mozilla0.9/
