Easy Java Simulations (Ejs) is a software tool designed for the creation of computer simulations. It is a media for making, doing , creating and best of all, it can be used as a modeling tool.  Construction, simulation, visualization, and analytic description of the physics model are linked during the creation process.  With Ejs, the task of creating a simulation is greatly simplified.  That is, the majority of the programming work is done by automatic code generation based upon text-based instructions, mathematic formula about the model and menu/mouse selections from the designer creating the graphical user interface for the simulation.  Java source code is generated automatically and compiled into class files. In addition, a jar file and the associated html pages are produced for users to view the simulation with a browser. This automatic code generation allows the Ejs user to concentrate on describing the model by defining the parameters related to the model, providing equations for the evolution of those parameters, setting the constraints between variables, and building a graphical representation. An additional advantage of using Ejs is that it causes the designer who is building the simulation to think through the problem in a new way. Ejs was developed for an Open Source Physics Project at the University of Murcia, Spain. Ejs, and the simulations created with it, can be used as independent programs under different operating systems, or be distributed via the internet and run within html pages by most popular web browsers.

Please check out [url=http://imej.wfu.edu/articles/2003/2/01/]Easy Java Simulations: An Interactive Science Learning Tool[/url]

The following is a flash movie shows you how to create simulation with EJS. (FInd out how easy it can be!)
[flash=600,400]http://www.phy.ntnu.edu.tw/ntnujava/swf/kepler_e.swf[/flash]
  1. Original author's web site [url=http://fem.um.es/Ejs/index.html]Francisco Esquembre [/url]. He is also a member of Conceptual Learning of Science[url=http://colos.org/] CoLoS group[/url]
  2. download Latest version of [url=http://www.phy.ntnu.edu.tw/demolab/download/ejs.zip]Ejs  [/url]
    Installation Procedure: Need Jav Run time version 1.5 or later!
    1. Unzip downloded file to any directory in your computer (for example:c:\) It will create a new subdirectory: Ejs
    2. Double Click Ejs/EjsConsole.jar to run it!
  3. Online paper  [url=http://imej.wfu.edu/articles/2003/2/01/index.asp]Easy Java Simulations: An Interactive Science Learning Tool[/url]
  4. online demo
  5. [url=http://www.phy.ntnu.edu.tw/demolab/download/EjsManual3.1.pdf]Ejs manual [/url]
  6. tutorial: movie files created with camtesia (Mbyte)