DynaDraw

DynaDraw is a dynamic drawing application based upon a program written in 1989 by Paul Haeberli. The program can be used to make a variety of drawing effects, but it is especially useful for calligraphy. The drawing works like a spring and mass system, as if your finger were pulling a weighted paintbrush attached to it with a spring. You can adjust the spring, mass and drag parameters to change the dynamic effect.