The Java JAR file in review The JAR file is an important artifact in the world of Agile software development in Java. Really, though, the JAR file is just a ZIP file with a different file extension.

How do you run a JAR file on Windows, Mac or Linux? Double click the JAR? Run the JAR at the command line? Several approaches will work if you have Java or the JDK installed.

A JAR file is an archive file but is more than a file compression format. Here's how to open, run, or execute JAR files.