Phototype is a client/server-side library, based on prototype, which supports all kinds of image manipulations. On the serverside the library is powered by combination of PHP/GD that renders the image. With phototype, you are able to rotate, resize, flip and do some other cool effects to images.

Requirements: Prototype Framework
Demo: http://ajaxorized.com/phototype-image-manipulation-with-javascript
License: GPL License