Browser vendors are moving away from plugin support. Because of this new trend, application developers will rely on plugin-free technologies like Java Web Start. To learn more how to deploy your applications using Java Web Start, check out the documentation available here.
Oracle plans to deprecate the Java browser plugin in JDK 9. You can now try the early access release of JDK 9. If you are looking to migrate from migrating Java Applets to Java Web Start, please see this whitepaper about migration.