Interactive online modeling environments are online web pages with an interactive graphical user interface for model input and control, dynamic graphs and tables for output, and animations. They are created to allow the user (student) control of a model or animation so they can perform virtual experiments. Interactive online modeling environments are typically written in JAVA or Macromedia Director programming languages. Most interactive online modeling environments are created to be platform and browser independent. However, there are still limited problems with some browsers/platform combinations. Although Java-Script (this is not related to JAVA) does not have animation capabilities it can be used to create interactive activities with text box input and output. Many interactive online calculators that can help students explore the behavior of equations and interactive online quizzes are created with Java-Script.