The Java SE Runtime Environment contains the Java virtual machine, runtime class libraries, and Java application launcher that are necessary to run programs written in the Java programming language. It is not a development environment and does not contain development tools such as compilers or debuggers. To run your application, a user needs the Java SE Runtime Environment, which is freely available from Sun. Or, you can redistribute the Java SE Runtime Environment for free with your application, according to the terms of the Runtime Environment"s license.