CartoonBuilder developers' page
Cartoon Builder allows you to create your own cell-animation sequences, by positioning and manipulating a playful cartoon character inside a filmstrip, and by using provided media assets -- backgrounds, characters in multiple poses, sound effects. You can play the sequence at different speeds, and save it. “Make Your Own” functionality lets you produce original cartoons that incorporate character poses, backgrounds and sounds you made yourself using other XO applications (Paint, Camera, Microphone, etc.).
This is a WorldWideWorkshop project - see the  page.