Mozilla has switched Firefox to a rapid release development cycle which means new versions will come more frequently. The non-profit organization has promised to push out a new stable build every six weeks.

What's New in Firefox 9:

  • Added Type Inference, significantly improving JavaScript performance
  • Improved theme integration for Mac OS X Lion
  • Added two finger swipe navigation for Mac OS X Lion
  • Added support for querying Do Not Track status via JavaScript
  • Added support for font-stretch
  • Improved support for text-overflow
  • Improved standards support for HTML5, MathML, and CSS
  • Fixed several stability issues
  • Please see the complete list of changes in this version. Web and extension developers should also view the curated list of platform changes. You may also be interested in the list of changes in the previous version.

    More detailed release notes are available here.