Kotlin 1.0 Release Candidate is Out!

Finally, Kotlin has graduated the Beta and we are happy to present the Release Candidate Build!

NOTE: as we announced earlier, RC requires all code to be recompiled to make sure no code compiled with older versions is kept around (please recompile even if you were on the EAP version!).

This blog post gives an overview of the changes made since Beta 4. Library changes are the biggest in this build. Also, some bugs have been fixed. Full list of changes is available here.

Kotlin 1.0 RC

See the discussions on Hacker News and Reddit.

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Kotlin Digest 2015

Kotlin’s adoption significantly increased in 2015, and we are especially grateful to our early adopters, who not only used Kotlin, but shared their experiences through different mediums. We’d like to highlight the most notable articles and videos of the past year.

By the way, you can join us on slack and subscribe to the #feed channel, where we push quite a bit of interesting content as it appears.

Kotlin Digest 2015

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Kotlin 1.0 Beta 4 is Out!

We are happy to announce Kotlin Beta 4, another step towards 1.0! We are now mostly focused on the infrastructure and future-proof changes. Full list of changes is available here. More details below.

It’s also time to let you know about what else we are going to do before 1.0. Continue reading

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Learn Kotlin with “Advent of Code”

Christmas is coming! Are you prepared? It’s time to gift yourself with a new language!
Have you already checked out the amazing series of puzzles “Advent of Code” by Eric Wastl? These tasks have pretty lean and expressive solutions in Kotlin due to it’s functional programming features.

Try to solve them all! In Kotlin!


You can write your solutions in IntelliJ IDEA Community Edition which is free and supports Kotlin out of the box.

Moreover you can solve tasks in the Kotlin playground right in your browser. We’ve added special template for “Advent of Code” puzzles:

Wish You a Merry Kotlin!

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Kotlin 1.0 Beta 3 is Out!

We are glad to present another update of Kotlin 1.0 Beta. We are working towards finalizing the standard library and getting rid of old deprecated constructs in the language, as well as bug fixes, performance improvements and future-proof checks.

Full list of changes is available here.
See closed issues here. Continue reading

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Kotlin Eclipse Plugin 0.5.0

New in this release

  • Kotlin Beta 2 support
  • Semantic highlighting
  • Rename refactoring
  • Mark Occurrences
  • Extract Variable refactoring
  • Navigation to Kotlin standard library sources

Drag to your running Eclipse workspace to install Kotlin Plugin for Eclipse

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Contest: Go Cross-Platform with Kotlin!

Hi All,

Have you ever heard about RoboVM? It lets you create beautiful native apps for iOS & Android, allowing you to share code between platforms. RoboVM translates Java bytecode into native ARM or x86 code.
The latest RoboVM release makes it super easy to get up and running with Kotlin! And today you have a good incentive to play with it, by taking part in the first ever Kotlin Mobile contest! Simply install the RoboVM plugin for IntelliJ IDEA or download RoboVM Studio, and create a cross-platform Kotlin app. Continue reading

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Kotlin 1.0 Beta 2 is Out!

The first update to our Beta is here! We are stabilizing, so it’s mostly bug-fixing and changes to the standard library.

Language changes

We are now enforcing single-instantiation inheritance constraint on type parameters: the same T can not have both List<Int> and List<String> as its upper bounds. This has been always forbidden for classes, now the same check applies for type parameters. Continue reading

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Webinar Recording: Functional Programming with Kotlin

The recording of our October 22nd webinar, Functional Programming with Kotlin, is now available on JetBrainsTV YouTube channel.

In this talk, Mike Hearn provides a brief introduction to programming in Kotlin via practical example: creating a textfield with the autocomplete suggestions while typing. Demo project is available on GitHub.

Topics covered include:

  • Use of functional transforms
  • Immutability
  • Lazyness and working with lazy infinite sequences
  • The use of funKTionale, a library that extends Kotlin with a few features known from Haskell
  • Pattern matching
  • Reactive user interfaces

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The Kotlin Language: 1.0 Beta is Here!

We are extremely pleased to present Kotlin 1.0 Beta for JVM and Android!

To recap: Kotlin is a modern programming language that JetBrains has been working on for quite some time now.

This post gives an overview of where we are and what’s coming next. Changes in this version are listed here.

The story behind Kotlin

Kotlin was conceived in 2010. Ten years of Java development led us to feeling that our productivity at JetBrains could be improved significantly by using a modern JVM language alongside Java. Having evaluated other available options, we decided that a new language was needed there, and we had the expertise and resources to create such a language. Our primary line of business is making tools for developers, and the guiding principle is that the best way to make an awesome product for the users is to make an awesome tool we need ourselves. This worked with IntelliJ IDEA, ReSharper, and many other IDEs, as well as TeamCity and other server products, so we set off to apply the same principle for another developer tool — a programming language. Continue reading

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