Java Web Start
JWS is a Java technology initiated by downloading and executing a JNLP file from a server. This causes the JRE to download and cache the Java application associated with the JNLP file. If you already have the latest version of the application, the cached version is run without downloading, so the application starts faster. The JNLP file may also be stored and run from a desktop environment, and will still check for the latest version of the application.
The jnlp file should start its associated Java application automatically. If not, locate the file and double-click it to run the application. Note that the jnlp file stores the location of the data, as well as the link to the application, so clicking on several links will result in multiple jnlp files with the same name and incrementing suffix, depending on the browser and operating system. Click on the most recently downloaded file (highest ordinal suffix) to load the last-clicked link.
Currently there is no Java version for 64-bit Chrome on the Macintosh platform. 64-bit Java is supported on Safari and Firefox on the Mac.
Downloaded Java apps are not supported on Android or iOS devices. Android is developed in an open source Google-derived remake of Java but the JRE is based on proprietary code belonging to Oracle.
Auto Start not working
Many browsers disable the auto-starting of downloaded jnlp files. Some workarounds have been published.