There's no actual lockin, it's just that JetBrains put a lot of resources into the IntelliJ plugin and the quality of that plugin is a large part of Kotlin's va

There's no actual lockin, it's just that JetBrains put a lot of resources into the IntelliJ plugin and the quality of that plugin is a large part of Kotlin's value. You can easily write Kotlin in any other editor of course, but the experience won't be as good. JB have a team of over 70 people I think working on Kotlin as this point, and the IDE plugin shares the compiler infrastructure, so they improve together. If you were trying to write a competitive plugin it'd be a lot of work. Of course, if your editor was written in Java you could also re-use the compiler infrastructure in the same way they do. Their planning is half internal/half external. There are public specs that get feedback for all language upgrades. How JB choose to prioritise is up to them, of course.