Tweener (caurina.transitions.Tweener) is a class used for creating tweenings and other transitions via actionscript code. The general idea is that dynamic animation and transitions (created by code) is easier to maintain and control, and more stable than timeline animation (since you can control it by time rather than by frames). Tweener is the spiritual successor to MC Tween. It follows Actionscript’s more strict OOP rules, and is released and maintained for both AS2 and AS3. Aimed both for designers and advanced developers, it still keeps the “one-line” design mentality used on MC Tween, but with a different, more fluid syntax (by way of an static class) that allows a wider control of how transitions are performed. Such characteristics weren’t possible on MC Tween due to the way the available parameters (and its order) were fixed by its syntax. Tweener downloads and documentation are hosted at Google Code.
Example from MC Tween: