http://www.mozilla.org/projects/firefox/

What's new in Firefox 1.5 Beta 1 since Deer Park Alpha 2:

- Automated update to streamline product upgrades. Notification of an update is more prominent, and updates to Firefox may now be half a megabyte or smaller. Updating extensions has also improved.

- Faster browser navigation with improvements to back and forward button performance.

- Drag and drop reordering for browser tabs.

- Improvements to popup blocking.

- Clear Private Data feature provides an easy way to quickly remove personal data through a menu item or keyboard shortcut.

- Answers.com is added to the search engine list.

- Improvements to product usability including descriptive error pages, redesigned options menu, RSS discovery, and "Safe Mode" experience.

- Better accessibility support including DHTML accessibility.

- Report a broken Web site wizard to report Web sites that are not working in Firefox.

- Better support for Mac OS X (10.2 and greater) including profile migration from Safari and Mac Internet Explorer.

- New support for Web Standards including SVG, CSS 2 and CSS 3, and JavaScript 1.6.

- Many security enhancements.