After a 2-year development cycle, Thunderbird 3.0 finally released in December 2009 with a bunch of new feature milestones. Step into the Thunderbird Time Machine and let’s revisit this groundbreaking version.

The Thunderbird Time Machine boots up Windows XP, and travels back to 2004 to pay respect to Thunderbird 1.0.

It’s the Summer of 2003. Linkin Park, 50 Cent, and Evanescence have top-selling new albums. Apple’s iPod hasn’t even sold 1 million units. Mozilla’s brand new web browser is still called Firebird. And a new cross-platform, open-source application called Thunderbird just debuted from the foundations of Mozilla Mail…