The Java Web browser plug-in just got its death notice. Oracle announced it's deprecating the browser plug-in this fall with the release of JDK 9, and removing it completely in a later release.
Oracle ending support for Java browser plug-in
Oracle said browser developers moving away from supporting NPAPI plug-ins was behind the move. Site designers have been moving away from plug-ins such as Java, Silverlight, and Flash because mobile devices don't support them, and those design changes have been carrying over to the standard versions of sites, too.
Oracle said on its blog,
With modern browser vendors working to restrict and reduce plugin support in their products, developers of applications that rely on the Java browser plugin need to consider alternative options such as migrating from Java Applets (which rely on a browser plugin) to the plugin-free Java Web Start technology.
NPAPI, or Netscape Plugin Application Programming Interface, was released in 1995 for Netscape Navigator 2.0 as a way to extend the browser's capabilities through plug-ins. It was later adopted by other browser makers, but now is being phased out in favor of content that doesn't require special plug-ins.
Java is considered a major security vulnerability and if you don't need it on your Mac, considering disabling or removing it. Apple has blocked Java plug-ins from running in Safari over security concerns more than once.