Pencil is an advanced drawing and animation tool that creates traditional, hand-drawn 2D animations and static sketches. Think of this animation/drawing application as an Etch A Sketch with colored sand on steroids. Pencil creates bitmap and vector images. Finished animations can be exported as a PNG image. Animated sketches can be exported in several handy Flash or Movie file formats. Pencil is a very impressive drawing tool. It imitates hand-drawn animation techniques. However, getting it installed was no easy task. 
