by Thomas Witelski (witelski@math.duke.edu) Department of Mathematics, Duke University, Box 90320, Durham, NC 27708-0320 Free software comes with no warranties. This is a freeware phase plane plotter for UNIX X-windows systems. It plots solutions of 2-d plane autonomous ODE systems. It is (hopefully) very easy to use and understand. It is primarily intended for student use in intro courses on diffential equations/dynamical systems or chaos. The program understands most of the usual simple functions, and it knows the constant pi, and it also has heard of the Heaviside step function h(x). It is still very much in the developmental stages. So I would appreciate comments/feedback on bugs, things you like, don't like, want in the program. Tom