Kotlin M6.1

What's new:

• Language features
  • else is not required in when-statements
  • Type argument inference uses smart casts
  • Ability to suppress warnings with [suppress("...")] annotation
  • Local returns in lambda expressions
• Compilation to JavaScript
  • Enums
  • Class Objects
  • Delegated properties
  • Multi-Declarations
  • SourceMaps
• IntelliJ Plugin Improvements
  • Automatic configuration of Maven and Gradle projects
  • Convert member function to extension function
  • Navigation to getters and setters of a delegated property
  • Navigation to iterator/next/hasNext in a for loop
  • Navigation to invoke() from a call site
  • Improvements on Find Usages including support for constructors and overrides

Read more in this blog post

Kotlin M6

What's new:

• Language features
  • SAM Conversions
  • Annotation improvements
  • Static fields visible from Java
• Android
  • Integration with Gradle for Android
  • Integration with Android Studio
• IDE features
  • Inline variable, Safe delete and other refactorings
  • TestNG support
  • Faster code completion

See a detailed description in this blog post.