The Ejs Standing Waves on a String model displays the motion of a standing wave on a string. The standing wave can be augmented by adding the zero line and the maximum displacement of the string. The number of standing waves shown can be changed via a slider. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting “Open Ejs Model” from the pop-up menu item. Ejs Standing Waves on a String model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_ehu_waves_standing.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for wave motion are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.