While we are still happy with Firefox 3, the team is now testing the next version 3.1. The Firefox 3.1 beta has been released with Windows, Linux and Mac OS versions. It is intended for developer testing. The new version will be using Gecko 1.9.1 engine. It have improvements in web standards which forms webpages in a better way. Other improvements include,

1. Text API for the element
2. Support for using border images
3. Support for JavaScript query selectors
4. Several improvements to the Smart Location Bar
5. A new tab switching behavior

The beta is now available to download right here.

[via Mozilla Developer News]