FEffects is a library that enables you to create visual transitions like motion-tweens for example.
The package actually offers tweens and Robert Penners' easings are used here.
It can be used the same way, in your flash, flash9 and JavaScript projects.

Install

In order to use FEffects, you need to install the library using haxelib, like that :

haxelib install feffects

Then you can use the library by adding -lib feffects to haxe commandline parameters.

Tutorial

FEffects is used especially to create visual transitions, but in fact, it's just a numerical value interpolation: The Tween class will compute the intermediate values according to the begin value, the end value the duration and the choosen easing function.