Where is Kotlin support for Eclipse and Netbeans?

Prove me wrong.

Do you use Eclipse? Have you looked at the available plugins?

There's nothing special about Kotlin. It's a bunch of libraries for runtime and compile time... like anything else you use.

It is my main Java IDE.

There is a difference between supporting a language with a Notepad++ like experience, and what JetBrains was doing before ramping down the Eclipse plugin team, as means to sell more InteliJ licenses instead.

What do you believe you are missing?

It compiles fine with Maven or Gradle, it provides auto-prompt/complete/hints. It just works.

Same experience as in InteliJ, which JetBrains no longer provides.

And above all, no crashes left and right.

I'll ask again more clearly - what is the "same experience" you are missing?

Kotlin is plugins for Maven/Gradle, and classpath libraries. There is no magic going on here...