Topograph is a machine for constructing surface.
Moving the cursor over the grid will place a
quantum of "energy" into the grid cell directly 
beneath the cursor. Consequently, this now 
energized cell redistributes the energy 
equally among its adjacent cells, which will in
turn do the same. Inversely, dragging the
cursor (moving it while holding the mouse
button down) over the grid will drain the
energy from the cell directly beneath the
cursor.

Topograph was written in the Java programming 
language. It is part of a series of Java works
titled kinograffiti.