There are over 2000 repositories on GitHub alone with Kotlin projects. These are just a few of them. If you have an OSS project in Kotlin or know of one, please add it.
Community-Maintained Links
You can find a community-maintained list of links to Kotlin projects, libraries and other resources at Awesome Kotlin.
Open Source Projects and Libraries
| Name | Description | Type |
|---|---|---|
| Spek | A Specification Framework | Library |
| Wasabi | An HTTP Framework | Framework |
| Ktor | Web application framework | Framework |
| Kara | An MVC Framework | Framework |
| Humanizer for JVM | Humanizer Library | Library |
| Kotlin-NoSQL | NoSQL MongoDB access for Kotlin | Library |
| FunKtionale | Functional Helpers for Kotlin | Library |
| KotlinPrimavera | Kotlin Wrapper for Spring Framework | Library |
| Sublime Package | A Sublime Package for Kotlin | Tools |
| Kotlin Vim | Kotlin Syntax Highlighter for Vim | Tools |
| Griffon Plugin | Griffon Support | Tools |
| Android Rivers | RSS Readers for Android | Android App |
| Stew | A simple Android app for soup.io | Android App |
| RxKotlin | Kotlin Bindings for RxJava | Library |
| Solr-Undertow | Solr Standalone Tiny and High performant server | Application |
| Yested | A Web Framework | Framework |
| Kotlin-Hashids | Library that generates short, unique, non-sequential hashes from numbers. | Library |
| Kotter Knife | Butter-knife view binding for Kotlin | Library |
| Android Kotlin Extensions | A collection of Android Kotlin extensions | Library |
| KAndroid | Kotlin library for Android | Library |
| Kovenant | Promises for Kotlin and Android | Library |
| Progress | Simple Progress tracking | Library |
| Injekt | Dependency Injection / Object Factory for Kotlin | Library |
| Fuel | HTTP Client library written in Kotlin | Library |
| Klutter | Small helper libraries for Kotlin, usually extensions to other libraries | Library |
| Kodein | Painless Kotlin Dependency Injection | Library |
| Kovert | An invisible REST framework for Kotlin | Library |
| khttp | HTTP client similar to Python's requests. | Library |
| Kobalt | A build system written in Kotlin | Build system |
| Klaxon | A JSON library written in Kotlin | Library |
| Result | The modelling for success/failure of operations in Kotlin | Library |
| ext4klaxon | Type Extensions (Long, Int, Enum, Date) for Klaxon | Library |
| Bubble | Library for obtaining screen orientation when orientation is blocked in AndroidManifest | Library |
| HamKrest | Self-describing matchers for testing and validation (a port of Java's Hamcrest to Kotlin) | Library |
| Kotpref | Android SharedPreference delegation for Kotlin | Library |
| KotliQuery | A handy database access library in Kotlin | Library |
| Zipangu | Easy to handle the information in the prefectures of Japan in Kotlin | Library |
| knit | JUnit API set for Kotlin | Library |
| khronos | An intuitive Date extensions in Kotlin | Library |
| TornadoFX | Lightweight JavaFX Framework for Kotlin | Library |
| Hexagon | A microservices framework in Kotlin | Framework |
| Fuse | The simple generic LRU memory/disk cache for Android written in Kotlin | Library |
| Discovery | Eventually consistent service discovery server | Application |
| KotlinTest | Kotlin port of the famous ScalaTest | Library |
| Black-and-White | A library of algorithms for the Black-and-White tree coloring | Library |