They aren't supported in Java 9.

Yes they are. They're deprecated, but not gone.

Not that it much matters, since Chrome doesn't support the NPAPI plugin, and FireFox is expected to drop support early in the new year, leaving Applets an essentially IE only thing.

Hopefully Java WebStart doesn't go anytime soon, I still rely on that for OOB management on my servers without needing to boot Windows and use IE + the .Net consoles.

Java Webstart is the official way for applet alternatives, according to the Java blog.

And in Java, anything deprecated is never really removed.

Not paying attention to the JEPs?

http://openjdk.java.net/jeps/277

There was a session at Java ONE about a set of API that will be gone in Java 10 after this gets introduced in Java 9.

Good. It was one thing we always disabled in our deployment of JRE. One less vulnerable entry point for those who needed it on their workstations.