Tweener and TweenLite have become the micro animation kits as well as micro kits you can make with Go base kits. TweenLite, TweenFilterLite and TweenMax divided up into different kits allows it to be embedded for banners or small assets easier if you don’t need the filters or other advanced tweens (this comes into play heavily with large games and asset collections when the compiled SWF each need the library). Tweener packs all features into one kit for simplicity. GreenSock kits are divided up for need. The comparison together is about the same but for basic tweens TweenLite is only 2k.

Performance is one area that the kits from GreenSock have really shined and since the addition of the speed tests and benchmarks it has become a great focus on showing how the open source kits are much better than bloated included animation calls in Flash and Flex defaults. I think all the kits have niches that they fit and Tweener and TweenLite are just very simple to use which adds alot to an animation kit success.

List of Animation Kits for AS3 (some for AS2 as well)

• Tweener
• GreenSock
  • TweenLite
  • TweenFilterLite
  • TweenMax (Speed Test)
• Go Base
• Twease
• AS3Easing
• Animation Package
• Animation System

If you are using the Flex of Flash default animation classes, I am sorry…