The Kotlin Blog

Kotlin Programming Language by JetBrains

Release

Kotlin 1.4.30 is now available. This is the last 1.4 incremental release, so we have lots of new experimental features that we plan to make stable in 1.5.0. We would really appreciate it if you would try them and share your feedback with us. We hope you enjoy testing out all these new updates, and please let us know what you think. What's changed in this release: Language features and compiler T

We’re planning to add new language features in Kotlin 1.5, and you can already try them out in Kotlin 1.4.30: Stabilization of inline value classes Experimental support for JVM records Experimental support for sealed interfaces and other improvements for sealed classes To try these new features, you need to specify the 1.5 language version. The new release cadence means that Kotlin 1.5 is going

We'll make the new backend Stable soon, so we need each of you to adopt it, let's see how to do it. We have been working to implement a new JVM IR backend as part of our ongoing project to rewrite the whole compiler. This new compiler will boost performance both for Kotlin users and for the Kotlin team itself by providing a versatile infrastructure that makes it easy to add new language features.

Kotlin 1.4.20 is here with new experimental features for you to try. Being open to community feedback is one of the Kotlin team’s basic principles, and we need your thoughts about the prototypes of the new features. Give them a try and share your feedback on Slack (get an invite here) or YouTrack. Here are some of the key highlights: Support for new JVM features, like string concatenation via in

In Kotlin 1.4, we’re adding new experimental ways for generating default methods in interfaces in the bytecode for the Java 8 target. Later, we’re going to be deprecating the `@JvmDefault` annotation in favor of generating all the method bodies in interfaces directly when the code is compiled in a special mode. Read more details of how it currently works and what will change, below. In Ko

Today we’re glad to present the last milestone preview of Kotlin 1.4 – 1.4-M3. In this post, we’ll guide you through the changes this preview brings to the Kotlin standard library. Other components are also getting updates in M3; we’ll cover them soon in another blog post with the release candidate version (1.4-RC), which will finalize the scope of Kotlin 1.4. The standard library changes in 1.4-

Right before the festivities start, we've managed to release the next milestone of Kotlin, adding dynamic types and more. Let's see what M10 brings us. (more…)

M9 has arrived and it's bringing many new features and important changes. We've already highlighted these and covered others in detail. Let's dig deeper into some of the other improvements. (more…)

We have a new web site and a new domain! It's Open Source It would make no sense to be developing a language that is Open Source and not having an Open Source web site and documentation. We worked by gradually porting all the old site from the previous platform to Jekyll. The new site is all written in Markdown (actually Kramdown, a flavour of Markdown) and hosted on GitHub. In fact, we've mad

It's been a really busy couple of months since the last release and we've been working hard on making substantial improvements, particularly in terms of speed. We have a lot of goodies for this release. Let's get started (more…)

Kotlin M7 is here and with it some long awaited features. Compiler and Language Changes Inline support One of the biggest features of M7 is support for inline functions. Kotlin encourages the use of higher-order functions (some people call this "functional style") which entails extensive use of lambda expressions. Starting with M7, you can declare a higher-order function as "inline" which means

Today we release Kotlin M6.2 which brings some interesting and important features. The newly released IntelliJ IDEA 13 is now supported too. Let’s take a look. (more…)

Two months ago we released M6 and we’re now ready with another update containing a bunch of goodies. (more…)

We’ve reached our sixth milestone, and with it, have some great features in store, both in terms of language improvements as well as tooling. (more…)

Kotlin M5.3 brings support for IntelliJ IDEA 13 and some new features for you to check out. We are moving towards powerful runtime support, including reflection and other framework-enabling features. This milestone marks our first steps in that direction. (more…)

Another update of Kotlin comes out today. Welcome Kotlin M5.2. (more…)

There have been enough little improvements since Kotlin M5 so that we are rolling them out as M5.1 today. Some of them are not so little in fact, like enabling the use of Scala libraries, such as Akka. This post gives a quick overview of these changes. (more…)

In two weeks from now it will be one year since Kotlin started out as an open source project. It's been a lot of hard work over this time, with a huge help of the community: we received 164 pull requests, which means a contribution every other day or so. Today we make another step and roll out Kotlin M5. This blog post covers the changes introduced in this release. (more…)

Today we roll out Kotlin M4 (from under snow). This post gives an overview of new features and other things this milestone brings. (more…)

Last time I wrote about a new exciting feature in "the upcoming Kotlin M3". Today, Kotlin M3 is not "upcoming" any more, it's here. This post gives an overview of the new milestone. (more…)

The Kotlin Blog

Release

1.4.30 Is Released With a New JVM Backend and Language and Multiplatform Features

New Language Features Preview in Kotlin 1.4.30

The New JVM IR Backend Is in Beta: Let’s Make It Stable Together

Kotlin 1.4.20 Released

Kotlin 1.4-M3: Generating Default Methods in Interfaces

Kotlin 1.4-M3 is Out: Standard Library Changes

M10 is out

M9 is here!

A New Open Source Web Site

M8 is out!

M7 Release Available

M6.2 Available

M6.1 Released

Kotlin M6 is here!

Kotlin M5.3: IntelliJ IDEA 13, Delegated Properties and more

Kotlin M5.2: IntelliJ IDEA 12.1 and Gradle

Kotlin M5.1

Kotlin M5 is Out!

Kotlin M4 is Out!

Kotlin M3 is Out!