The days of bloated, bug ridden, error prone web browser plugins are finally and truly numbered. Just last month, Adobe has practically started Flash's retirement from the web, pushing instead for a more standards-friendly HTML5. Now Oracle is doing the same, somewhat. Of course, it isn't dropping the ball on Java entirely but it is announcing the inevitable and probably demise of the Java web browser plugin. That said, what it recommends as a replacement is still a Java-based technology for launching full applications from a browser link.
Flash and Java are the two biggest holdouts in ridding the Web of plugins. No one will perhaps deny their usefulness back in they youth, giving birth to hundreds of interactive web sites, powerful web applications, and pushing the boundaries of the Web itself. Fast forward to today, however, such plugins have become the biggest source of security risks over the Internet. But while Flash has been more or less supplanted by HTML5, many websites, especially those used in Intranet or business settings, still made use of plugin based Java apps.
To some extent, Oracle really has no choice but to retire the plugin. Modern browsers these days have cut off support for NPAPI, or the Netscape Plugin API, the almsot ancient feature that allowed the likes of Flash and Java to operate inside web browsers. Without that, those plugins and the apps that depend on them wouldn't work.
Of course, Oracle doesn't want users to abandon using Java for the web all together, so it offers Java Web Start or JavaWS as an alternative instead. Like the old Java applet, JavaWS apps of course use Java and can be launched by clicking a link on a web page. Unlike the old way, however, JavaWS run outside of the browser and as standalone apps of their own, though still within a Java virtual machine sandbox. If the JavaWS app hasn't been installed yet on the computer, clicking on a link will first download the app and the automatically run it. JavaWS is advertised to be more robust and apps are more easily maintained and upgraded than Java web applets.
That said, those businesses that still use old applets will still be able to use those as long as they don't upgrade their Java version, or their web browser for that matter. That, of course, leaves them in a sort of no man's land when it comes to security fixes and updates. The Java web plugin will be deprecated starting JDK version 9, which is scheduled to be released sometime in September. It will be completely removed in both JDK and JRE in a still undetermined future release.