To run ModTest under Windows, you can use the Windows Run dialog or double-click on the icon or filename.

To run ModTest under other operating systems (or from a Windows command window) use the command:

You will, of course, need to use the full pathname for the modtest2.15.jar file if it's not in your current directory. You will probably want to create a shortcut, launcher, shell script, or whatever to save you having to keep typing the above command.

To exit from ModTest, select the File → Exit menu item or click the close button of the main window.