It was expected to be released in early august but it has arrived early. Firefox 3.1 is nicknamed as Shiretoko. The release note says that current users of Mozilla Firefox should not use Shiretoko Alpha 1 but I have found it to be stable. One of the most eye catching features that has been added is the new tab switching interface which  allows for page thumbnails to be browsed when switching. The other major feature is the enhancements to the syntax used for searching in the Smart Location Bar.

The best thing of this version is that  installing it won’t overwrite your existing Firefox 3.0 install, so you are free to experiment. This version also includes some additional CSS3 implementations. So in short it includes the following features

1. New tab Switching interface

2. Enhancement to the smart Location Bar

3. Support for using border images

4. Support for Javascript query selectors

5. Text API for the <canvas> element

6. Web standards improvements in the Gecko layout engine

You can download it for Windows, MAC OS X and Linux

Download here