Performance: Firefox is built on top of the powerful new Gecko platform, resulting in a safer, easier to use and more personal product for open source browser.

Security: Firefox raises the bar for security. The new malware and phishing protection helps protect from viruses, worms, trojans and spyware to keep people safe on the Web for its security centre.

User Experience: The enhancements to Firefox provide the best possible browsing experience on the Web. The new Firefox smart location bar, affectionately known as the "Awesome Bar," learns as people use it, adapting to user preferences and offering better fitting matches over time.

Customization: Everyone uses the Web differently, and Firefox lets users customize their browser with more than 5,000 add-ons and plugins. Use personally or officially can change its log easily.

Download this software for free
Source: http://www.mozilla.com/firefox/