A new Kotlin release, 1.2.20, offers a number of bug fixes and tooling updates, including IDE support for a new style guide and incremental compilation for Android and mixed Kotlin/Java projects. (A full changelog is available, of course, on GitHub.) “Compilation performance continues to be a major focus for us, and in this release we’ve mostly delivered improvements related to the Gradle plugin,” read the official blog posting accompanying the release. “If you’re using Gradle 4.3 or newer and the build cache is enabled (it’s not by default, requires 'build-cache' or 'org.gradle.caching=true'), the plugin will reuse compilation results from previous executions of the Kotlin compile task.” It seems that Kotlin’s release cadence is accelerating, perhaps due to its new status as an official Android language. Late November saw the debut of Kotlin 1.2, termed a “major release,” with features such as the ability to reuse code between JavaScript and the JavaScript Virtual Machine (useful for writing application logic once, then reusing it across the entirety of the app); that’s in addition to faster compilation times. The language's interoperability with Java is a major selling point. Android Studio 3.0, the most recent version of Google’s IDE for Android development, includes a conversion feature for those developers who wish to migrate Java-based projects to Kotlin. With Google solidly in its corner, Kotlin has seen its profile rise; it was one of two candidates (alongside C) for TIOBE’s annual Programming Language of the Year. If you’re interested in exploring the building blocks of the language, including its objects and classes, delegated properties, and basic functionality, check out this brief developer’s introduction to Kotlin. And if you’re already using Java, Kotlin offers some pretty good reasons to switch, including type safety in collections and the ability to compile to JavaScript (and with Kotlin/Native to binary).