'''Java Network Launching Protocol''' ('''JNLP''') is a closely-related concept that is often used interchangeably with the term "Web Start." It is the protocol, defined aswith an [[XML]] file formatschema, that specifies how Java Web Start applications are launched. JNLP consists of a set of rules defining how exactly this launching mechanism should be implemented. JNLP files include information such as the ___location of the [[Jar (file format)|jar]] package file and the name of the main class for the application, in addition to any other parameters for the program. With a properly configured browser, JNLP files are passed to a Java Runtime Environment which in turn downloads the application onto the user's machine and starts executing it. JNLP was developed under the [[Java Community Process]] as JSR 56, which includes the original 1.0 release, the subsequent 1.5 maintenance release, and as of [[2006]], the pending 6.0 maintenance release. JNLP is free; developers are not required to pay a license fee in order to use it in programs.
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 is needed to run a given program. The user does not have to remain connected to the Internet to execute the downloaded programs, because they execute from a locally-maintained [[cache]]. Finally, automatic updates of the software from the Web are available when the user is connected to the Internet, thus easing the burden of deployment.
