http://www.mozilla.org/releases/

* Mozilla Composer now implements one button publishing which allows you to save html documents directly to web sites where you have an established account.
* Our most frequently reported bug has been fixed. Viewing the source of a cgi generated page now works properly.
* The menu bar and context menus have been reorganized for improved usability.
* Mozilla now implements LDAP over SSL and allows LDAP Address Book replication.
* Mozilla now implements Mail Return recipts.
* Improvements to the UI for secure S/MIME mail.
* The preferences dialog now allows you to set a minimum font size for web content.
* On Microsoft Windows, mail users get animated alerts when they receive new mail.
* There is a new Download Manager, found under the Tools menu.
* Checking the File as group box in the File Bookmark dialog creates a bookmark group for all the tabs in that window. Opening the bookmark group in a new window opens a tab for each of the pages in the group and loads that page.
* The last of the XUL 1.0 syntax changes have landed.
* The following JavaScript statements are now acceptable, as they are with Netscape Navigator 4.7 and Internet Explorer 6:
for(i in undefined){}
for(i in null){}
var obj; for (i in obj){}
* Improved GB18030 support -- the Unicode surrogate range support is now available on Windows.
* Linux scaled bitmap font support is available This improves quality of bitmap font display even when a font does not contain embedded bitmap fonts in many different sizes.
* Fixed several bugs for Chinese IME on Windows and other platforms.
* There is now a preference to match the browser's default locale/region to the operating system default. In all.js:
pref("intl.locale.matchOS", false);
When its value is "true", browser will find the system's locale and set its UI language and region content to match it. For example, when installing on an English (US) system, on start up, the client will use English as its UI language and US as its region locale until a user profile is selected. If a (pair) of locale is defined in the selected profile, browser will honor the profile locale. In addition, when cmdline switches, '-UILocale' and/or 'contentLocale', are present, the cmdline switch takes precedence. (Bug 121744)
Note: Having this preference on is an expensive operation. Therefore, when this preference is "true", there will be approximately a 30% increase in startup time.