Software applications for teaching systems concepts

Systems concepts like nonlinearity and feedback are relevant in many fields, but interactive software to demonstrate these concepts are uncommon. Three mini-applications are discussed. These applications are relatively simple in programming and design. The magic is in the assignments and how students go through a process and are able to play with and modify the virtual systems captured by the mathematics of the software. Concepts such as complexity, mutation rate, equilibrium point, leverage points and delayed-response come to life. These software mini-applications differ from commercial systems-modeling software in that they are simple free, easy to develop or alter, and can be used for specific assignments without themselves requiring a high learning curve. The research aspect involved has been in designing and refining the process students go through to maximize what they learn from working with the software, so they understand the concepts in class.