[watwut]

Kotlin. I switched to Intellij due to Kotlin, in is slow in Eclipse

But seriously, Eclipse was helping me more then Intellij does and has better defaults. It shows all errors and warnings at once etc. Even things Intellij actually has like call hierarchy tend to be sort of hidden by default.

[pjmlp]

"The next thing is also fairly straightforward: we expect Kotlin to drive the sales of IntelliJ IDEA. We’re working on a new language, but we do not plan to replace the entire ecosystem of libraries that have been built for the JVM. So you’re likely to keep using Spring and Hibernate, or other similar frameworks, in your projects built with Kotlin. And while the development tools for Kotlin itself are going to be free and open-source, the support for the enterprise development frameworks and tools will remain part of IntelliJ IDEA Ultimate, the commercial version of the IDE. And of course the framework support will be fully integrated with Kotlin."

From https://blog.jetbrains.com/kotlin/2011/08/why-jetbrains-need...