Yahoo! has publicly launched two new (previously internal) libraries
calibre is a free and open source e-book library management application.
This is A pathfinding library. It has simple API for easy use in games
Lightweight GUI framework for haXe targetting Flash 7, Flash 8 & Flash 9
Asynchronous Unit Test Framework for haXe
Tweener (caurina.transitions.Tweener) is a Class used to create tweenings and other transitions via ActionScript code for projects built on the Flash platform. It's released and maintained for these versions: