Besides now enabling H.264 / GStreamer support in the official Firefox Linux builds, other changes include:
- Mozilla's Social Share API functionality is now exposed to developers.
- There's new mixed-content blocking that's enabled for fending off man-in-the-middle attacks and HTTPS eavesdroppers.
- The HTML5 input tag now supports the range type.
- A global browser console is now available to Firefox web developers.
- The HTML blink tag and blink CSS decoration have been finally removed.
Other changes found in the first Firefox 23.0 Beta can be found at Mozilla.org.