New features

Malware Protection: malware protection warns users when they arrive at sites which are known to install viruses, spyware, trojans or other malware.

Anti-virus integration: Firefox will inform anti-virus software when downloading executables.

Resumable downloading: users can now resume downloads after restarting the browser or resetting your network connection.

Places Organizer: view, organize and search through all of your bookmarks, tags, and browsing history with multiple views and smart folders to store your frequent searches. Create and restore full backups whenever you want.

Read More New features

Also read Known Issues if you are planing to install