Transit is a jQuery library for using CSS animations and transforms together with jQuery’s native, powerful features.

Transit’s syntax pertains to jQuery’s .animate, and improves the CSS manipulation capabilities of both jQuery and CSS by taking the best from both.

A total of 11 transformations are available. Among the most notable transformations are rotate3d; perspective; and scale.

Animations can be chained and laced with CSS goodness (e.g., change the opacity or color of an element).

• Website: http://ricostacruz.com/jquery.transit/

$fx is a slick JavaScript animation library for basic CSS transforms and timeline-based animations.

The library offers both working withing a timeline and in parallels.

There are numerous callbacks that help adjusting the script’s behavior.

$fx is especially useful if you want to add a parallax effect to your website; however, this library is useful for other everyday web chores, especially CSS transforms.

• Website: http://fx.inetcat.com/

jsMorph is a small JavaScript framework for creating JS-powered animations in an intuitive context.

jsMorph is a framework that deals with “old-school animations”, or animations done with pure JavaScript, not HTML5 or CSS.

Although using jsMorph for games or complex applications, the features the framework offers (seamless tweening, unit conversion, adjusting the render speed) make this framework more than worth a try.

• Website: http://jsmorph.com/
• Demo: http://jsmorph.com/demos.html

Timeline.js is a JavaScript library that employs easing animations and Flash-like GUI to create complex and long animations (as well as shorter ones!).

You can add keyframes, add animations, and basically create complex, keyframe-based animations with writing very little code — you only have to write the objects and add them to the animation.

Once you’ve finished with your animation, you can export code for making a non-GUI page.

Use Timeline.js for easily making JavaScript animations.

• Website: http://marcinignac.com/blog/timeline-js/
• Demo: http://vorg.github.com/timeline.js/examples/cssAnimation.html

Firmin is a JavaScript animation library that uses CSS transforms.

Firmin.animate(document.getElementById("an-element"), {
skew:   {x: "15deg", y: "30deg"},
rotate: "45deg"
});

// will yield the same results as CSS’s

 #an-element {
transform: skew(15deg, 30deg) rotate(45deg);
}

Firmin weighs a mere 8.3 kb when packed, and allows using extensive transform properties.

Besides, Firmin doesn’t require jQuery or any other libraries — it’s dependency-free.

Firmin supports all webkit browsers: Safari 4 and 5, Mobile Safari, and Google Chrome.

The plugin has an extensive documentation, and you can use it for smaller projects as it’s not that complicated.

• Website: http://extralogical.net/projects/firmin/

If your application has a list of items which are divided into categories, maybe you’d want to add something eye-candy-ish when a category is changed?

jQuery.Quicksand is a plugin for reordering items (icons, posts, products, etc) in a very pleasant way.

The Quicksand plugin adds an enormous lot to the user experience with eye-candy animations.

The plugin has some options, too: auto-adjust item height for them not to break out of the container; specify the reorder animation’s duration; and choose easing options for different transitions.

• Website: http://razorjack.net/quicksand/index.html