Lets build tweening library for Haxe and OpenFl. It's called Go!. Like Everybody in the place, lets Go.
It's easy to remember: you want to tween/animate something ... lets.Go.to()
Animate a sprite in 1.5 second to x postion 100
Go.to(sprite, 1.5).x(100); // or Go.to(sprite).duration(1.5).x(100);Animate a sprite in 1.5 second to x and y postion
Go.to(sprite, 1.5).x(100).y(200);Animate a sprite in 1.5 second to x and y postion and call function when animation is done
Go.to(sprite, 1.5).x(100).y(200).onComplete(onCompleteHandler, ['hello']);Rotate an object in degrees
Go.to(sprite, 1.5).rotate(360);Change the alpha of an object (value from 0 to 1)
Go.to(sprite, 1.5).alpha(.5);Change the scale of an object (value 1 is original scale/100% , 0.5 will be 50%, 2 will be 200%)
Go.to(sprite, 1.5).scale(.5);Delay an animation for 2 seconds
Go.to(sprite, 1.5).scale(.5).delay(2);Yoyo an animation (play the animation and reverse it back to the original values)
Go.to(sprite, 1.5).x(100).yoyo();Delay an animation for 3 seconds and then start
Go.to(sprite, 1.5).x(100).delay(3);Change default easing
import lets.Go; import lets.easing.Elastic; Go.to(sprite, 1.5).x(100).ease(Elastic.easeOut);
A good way of testing how a tweening libraries performes is a stress-test.
But do you really want to move 1000 objects at the same time?
Well you can with Go, but Actuate is better at it.
The reason for this is probably because it has optimazation specific for flash, and the stress-test is in flash!
I know there are more tweening engines out there, so add them here (if you feel the need).