Varpanel is a functional replacement for the built-in environment variable editor. It is a Control Panel applet. Hence Var for environment variables, panel for Control Panel applet. Varpanel knows about environment variables by name. It knows that PATH is a list of paths separated by semi-colons. It knows that JAVA_HOME specifies exactly one PATH. Based on the type of the environment variable Varpanel allows you to invoke an appropriate editor.