Littlebird is a Thunderbird theme featuring icons from art.gnome.org.
One of the best things about Littlebird is that it's very easy to install. The installation process has been thoroughly tested and works flawlessly for both TB 1.5.0.7 and TB 2.0beta1. To get started, simply download the entire jar file onto your computer (it should be 317.688 bytes in size).
Once you have the jar file, you can install Littlebird within Thunderbird itself. To do this, go to Tools/Themes or Tools/Addons, and select 'Install'. Then, find the jar file on your computer and click 'Open'. Thunderbird will take care of the rest, and you'll need to restart the program to finish the installation.
As far as requirements go, Littlebird is designed to work with Thunderbird 1.5 - 3.0a1, so it's compatible with a wide range of systems.
Overall, Littlebird is a great theme for anyone who wants to add a bit of style and flair to their Thunderbird experience. And with the recent update to TB 2.0b1, there's never been a better time to give it a try.
Version 2.0 1.7: N/A