Image auto sizing allows a user to toggle between full-sized images and images sized to fit the browser window. To give it a try, load a large image into the browser window or size the window to be much smaller. Now clicking on the image will alternate between auto-sized and full-sized.The feature can be disabled (or enabled) from the Appearance panel in Preferences.
Mozilla Mail's junk-mail classification is mostly complete. Users can now automatically move junk mail to a spam folder.
Users can now "dynamically" switch profiles. To give it a try, from the tools menu select "Switch Profile..."
Find as you type, formerly known as type ahead find, has a new preferences panel (Advanced: Keyboard Navigation).
When installed, Chatzilla now has a normal Mozilla preferences panel.
about :config, the listing of most of Mozilla's preference settings is now editable. Power users can now tweak just about every pref available without opening prefs.js in a text editor. Warning: tweaking some of these prefs may break Mozilla completely. Use at your own risk.
This release of Mozilla marks the kickoff of a research project to apply machine learning to improve the browser's autocomplete feature. The project's first phase needs as many Mozilla users as possible to participate in collecting data. All you need to do is turn on a pref, use this build for daily browsing for a couple of weeks, zip up a data file on your local drive, and submit it online.

Download :
Mozilla 1.3 Linux
Mozilla 1.3 Windows