DsTool (alternate , alternate ), originally written at Cornell by Mark Myers, Rick Wicklin and Patrick Worfolk, it was improved and modified by contributions from Allen Back and the staff of the former Geometry Center at the University of Minneapolis, is a computer program for the interactive investigation of dynamical systems. It includes a user interface written in Tk.
DsTool allows one to draw trajectories and find fixed points or bifurcation points. Dynamical systems arise in many disciplins of physics, biology and chemistry - basically always whenever something can be described by a set ordinary differential equations. The methods employed by the theory of dynamical systems allow to compute important properties directly without the need for long brute-force simulations.