What is Tweener?

Tweener is a JavaScript library for doing animations. It can smoothly interpolate numerical variables between two values. It is an implementation of Caurina tweener and has the same syntax. Tweener has more good properties:

Tweener uses window.requestAnimationFrame() function for animations, instead of classic setTimeout(). This new function of HTML5 makes animation fully synchronized with display redrawing frequency, everything will be very smooth.
Tweener is very small - it is under 10 kB.
Tweener is written very procedurally. No anonymous functions, no messing up with new objects. Even intensive tweening does not drain CPU.
Tweener is tweener, that's why it is called Tweener in JavaScript. You don't have to write TweenSpecial.xyz(), JSTweener.xyz() or SuperTweenForJS.xyz(). You just write Tweener.xyz().

Tweener is located under a short URL http://tweener.ivank.net/t.js

Usage

<script type="text/javascript" src="http://tweener.ivank.net/t.js"></script>

    var o = {x:100, y:200};
    Tweener.addTween(o, {x:400, y:500, time:2, delay:1, transition:"easeOutBounce"});
	
    // - parameters of "o" will be changed in 3 seconds

There is a demo of using Tweener for animation.

Discussion

Not all functionality of Caurina tweener is implemented in Tweener. If you want something new, or you find a bug, let me know.