Google today announced Kotlin as its official language for writing Android apps. Kotlin which is built by Jet Brains, the developers of the Jet Brains IDE that Android Studio is based on.
— Android (@Android) May 17, 2017
Kotlin runs on the JVM (Java Virtual Machine), and it’s already possible to use Kotlin and other JVM languages for Android development.
Google describes Kotlin, which is an open sourced project under the Apache 2.0 license, as “a brilliantly designed, mature language that we believe will make Android development faster and more fun.”
To get started with Kotlin, download the Android Studio 3.0 preview, open one of your existing Java files, and then choose “Convert Java File to Kotlin File” in the Code menu. Android Studio will walk you through adding Kotlin dependencies into your project and convert the code to functionally equivalent Kotlin code.