Processing

still image:

http://sweb.cityu.edu.hk/50676432/processing/still1/applet/index.html
http://sweb.cityu.edu.hk/50676432/processing/still2/applet/index.html

interactive animation:

http://sweb.cityu.edu.hk/50676432/processing/interactive_animation/applet/index.html

Hand drawing animation