Where do the automatic software updates from Sun come into play?
Java Web Start provides application providers the ability to target a specific version of the Java Runtime Environment for their applications. For example, an application provider may develop, test, and deploy an application based upon version 1.3.1 of the JRE. If the application provider then wishes to take advantage of new functionality in a newer release of the JRE, such as version 1.4, the application provider simply changes the target JRE in the JNLP file from 1.3.1 to 1.4. The next time a user runs the application, Java Web Start will detect that the application should now be run on version 1.4, and will automatically download and install version 1.4 if it is not already present on the client machine. Sun Microsystems, Inc. does not proactively and automatically initiate software updates of the JRE. An updated JRE will only be downloaded and installed when a user attempts to run a Java Web Start enabled application that requires a version of the JRE that is not present on the cli
