Important Web Start features include the ability to automatically download and install a JRE in the case where the user does not have Java installed, and for programmers to specify which JRE version a given program needs in order to execute. The user does not have to remain connected to the Internet to execute the downloaded programs, because they execute from a locally maintained cache. Updates of the software download from the Web and become available when the user has a connection to the Internet, thus easing the burden of deployment.