Kotlin could easily end up "the next groovy", but it might also end up the next Java, or at least maintain its edge against Java. Java is rapidly improving, an

Kotlin could easily end up "the next groovy", but it might also end up the next Java, or at least maintain its edge against Java. Java is rapidly improving, and significant resources are being invested into that effort. To remain relevant Kotlin will have to keep up with Java's improvements, and will also have to retain enough killer features that differentiate it from Java. Java is going to retain backwards compatibility, as they always have. This is a double-edged sword, of course. It holds Java back from fixing some its most glaring issues, but also keeps people in the ecosystem, and demonstrates desirable stability. Kotlin, on the other hand, could more easily introduce big, breaking changes. The Kotlin world is more keen on the cutting-edge, and would probably switch to a "Kotlin 2" without much resistance. Plus, JetBrains is extremely well-equipped to provide tools for auto-upgrading old code.