Over the years, I've seen quite a few open source tweening engines pop onto the scene, get some buzz, and then gradually stagnate and fade off the scene. Many stay in Beta for ages. Some contain known, unpatched bugs. The community usually does a good job of eventually recognizing quality solutions and gravitating towards them, but there are always people who try out the "latest and greatest" thing, only to be disappointed in the end as it stagnates or fails to mature. Don't get me wrong - I'm NOT saying all other tweening projects have suffered this fate or are "bad" in some way. In fact, I have spoken directly with some of the authors like Grant Skinner (GTween), Zeh Fernando (Tweener), and Moses Gunesh (Fuse, GoASAP). I have the utmost respect for each of them, and this article isn't meant to diminish anyone's hard work or generosity in the least. From my perspective, however, there are some common frailties of open source projects in general that I have observed, and my goal has simply been to figure out a way to protect the GreenSock Tweening Platform from falling victim to them. I have learned that one of the key factors in keeping a project like TweenLite thriving is actually the licensing model.

You can also scale or stretch DisplayObjects using the LiquidArea class which allows you to define a rectangular area that expands and contracts as the stage resizes, and you attach DisplayObjects so that they fill the area, scaling in any of the following modes: STRETCH, PROPORTIONAL_INSIDE, PROPORTIONAL_OUTSIDE, WIDTH_ONLY, or HEIGHT_ONLY. For example, you could have a bar snap to the bottom of the screen and stretch horizontally to fill the width of the stage. Or add a background image that proportionally scales to fill the entire stage.