Thunderbird 3 beta 3 is now available to download for Windows, Mac, and Linux users. The beta introduces some significant improvements to the open-source desktop client, from performance to interface.

The new beta is built on Mozilla's Gecko 1.9.1.1 platform, keeping it up to date with the latest changes that affect Firefox. Mozilla also claims that there are more than 500 changes in this version, and hints at more alterations to come by stating in a press release that many of them are ''la...