2010:

  • Kotlin Project Starts: JetBrains begins development on Kotlin. The project aims to create a concise, elegant, expressive, and Java-interoperable language to reduce boilerplate code and introduce new constructs like higher-order functions.

July 2011:

  • Project Kotlin Public Release: JetBrains initially releases the language under the name “Project Kotlin.”

February 2012:

  • Kotlin Open-Sourced: JetBrains open-sources the Kotlin project under the Apache 2 license.

February 15, 2016:

  • Kotlin 1.0 Released: Kotlin reaches its first major milestone with the official 1.0 release, signalling its readiness for production use. It is highlighted as a pragmatic programming language for the JVM and Android, focusing on interoperability, safety, clarity, and tooling support. JetBrains reconfirms its long-term commitment to the project.

April 22, 2018 (or earlier):

  • JetBrains’ Business Strategy for Kotlin Discussed: An article discusses JetBrains’ underlying business motivations for inventing and promoting Kotlin, beyond just developer productivity. These motivations include increasing the market share of JetBrains IDEs, preventing customer leakage to competitors, and reducing marketing effort for other tools by migrating developers to an in-house language easier to support.

Summer 2018:

  • Early Kotlin Multiplatform Library Ecosystem: There are approximately five published Kotlin Multiplatform libraries, including Multiplatform Settings and SqlDelight.

June 7, 2019:

  • Andrey Breslav Interview: An interview with Andrey Breslav, the lead developer of Kotlin, is published, discussing the origins of the language at JetBrains during his PhD.

Google I/O 2019:

  • Android Kotlin-First Announcement: Google announces that Android development will be increasingly Kotlin-first, committing to designing new Android development tools and content with Kotlin users in mind, while still supporting Java. Google co-founds the Kotlin Foundation and invests in improving compiler performance and build speed.

April 2020:

  • Kotlin Slack Membership: The Kotlin Slack community reaches close to 30,000 members, indicating a vibrant and growing community.

October 31, 2022:

  • Kotlin Multiplatform Mobile Beta Announced: The Kotlin Multiplatform Mobile (KMM) Beta is released, marking a significant improvement in the ecosystem. This includes a new Kotlin/Native memory manager with a garbage collector similar to JVM, improved Xcode integration (supporting Cocoapods and Swift Package Manager), and enhanced API surface exposure to Swift.

2022 (approximate):

  • KaMP Kit Ecosystem Growth: The ecosystem of starter projects and templates for Kotlin Multiplatform has significantly expanded, with KaMP Kit remaining a good option.
  • Kotlin Multiplatform Library Growth: Over 1000 library artifacts targeting iOS, Android, or JVM are available on Maven Central. Large SDK vendors like Realm and Sentry begin including Kotlin Multiplatform in their offerings.

September 2024:

  • Previous Kotlin Roadmap Update: JetBrains’ Kotlin roadmap was last updated, outlining key priorities and completed items.

February 2025:

  • Current Kotlin Roadmap Update: The Kotlin roadmap is updated, detailing key priorities such as language evolution, Kotlin Multiplatform (including direct Kotlin to Swift Export), and the experience of third-party ecosystem authors. New items are added to the roadmap, including finalizing JSpecify support, deprecating the K1 compiler, promoting Kotlin/Wasm to Beta, improving IntelliJ IDEA support for Kotlin/Wasm, and adding gRPC support to Ktor.

June 23, 2025:

  • Kotlin 2.2.0 Released: The latest official version of Kotlin, 2.2.0, is published by JetBrains.

June 27, 2025:

  • Android Developers Documentation Update: Android’s Kotlin-first approach documentation is last updated, reiterating Google’s commitment to Kotlin and highlighting its benefits like conciseness, safety, interoperability, and structured concurrency. It also notes that over 70 Google apps are built using Kotlin.

Ongoing:

  • Kotlin for Enterprise Applications: Kotlin is supported for server-side, client-side web, Android, and multiplatform library development.
  • Kotlin Learning Resources: A variety of online courses, books, and community platforms (forums, StackOverflow, Slack, User Groups, Meetups, KotlinConf) are available for learning and engaging with Kotlin.