The Shortcut Pane for ThunderBird extension brings some of Outlook's outlook bar functionality to ThunderBird. It is compatible with ThunderBird 0.8 - 1.5+.
In terms of system requirements, you'll need to have ThunderBird 0.8 - 1.5+ installed in order to use this extension. Once that's in place, though, you'll be able to enjoy the benefits of the Shortcut Pane for ThunderBird and all of its capabilities.
Overall, if you're looking to enhance your ThunderBird experience and bring a little bit of the functionality of Outlook along for the ride, the Shortcut Pane for ThunderBird is definitely worth a try. Give it a shot and see if it's the right fit for you and your needs!
Version 0.0.3: N/A