Java Network Launching Protocol

The Java Network Launching Protocol (JNLP) is the file format used by Java Web Start, a Java component that allows programs to be run outside of the browser (i.e. not as applets) but still in a sandbox. Users download the JNLP file and give it to an interpreter, which in turn downloads resources (Jar files, splash screens, etc.) whose URLs are listed by the file, and runs them. JNLP is based on XML. Java Web Start, like the applet system, eventually fell into disuse, and it was finally removed in Java version 11 in 2018.

Extensions
JNLP files use the extension ".jnlp".

Identification
JNLP files have the XML doctype "jnlp". The root element has the tag "jnlp".

Specifications

 * Directory of specifications (some old ones are only available through the Wayback Machine)
 * Version 6 document type definition

Samples

 * crossftp.jnlp
 * josm.jnlp

Software

 * NetX - currently maintained as part of IcedTea after the original was abandoned
 * Debian package icedtea-netx
 * Official Java releases before 11

Links

 * Java 8 Java Web Start documentation
 * Java 1.4 developer documentation
 * How To Run JNLP Files Under Ubuntu/Linux Mint
 * Java Web Start