Core functions and types, available on all supported platforms.

Library support for the Kotlin annotation facility.

Access to top-level properties (document, window etc.) in the browser environment.

Collection types, such as Iterable, Collection, List, Set, Map and related top-level and extension functions.

Helper functions for creating Comparator instances.

Utility functions for concurrent programming.

Experimental DSL for declaring custom function contracts.

Basic primitives for creating and suspending coroutines: Continuation, CoroutineContext interfaces, coroutine creation and suspension top-level functions.

Low-level building blocks for libraries that provide coroutine-based APIs.

Utility functions for working with the browser DOM.

Experimental APIs, subject to change in future versions of Kotlin.

IO API for working with files and streams.

Functions and other APIs specific to the JavaScript platform.

Functions and annotations specific to the Java platform.

Mathematical functions and constants.

Standard implementations of delegates for delegated properties and helper functions for implementing custom delegates.

Provides the default generator of pseudo-random values, the repeatable generator, and a base class for other RNG implementations.

Ranges, Progressions and related top-level and extension functions.

Runtime API for Kotlin reflection

Extensions for Kotlin reflection provided by kotlin-reflect library.

Runtime API for interoperability between Kotlin reflection and Java reflection provided by kotlin-reflect library.

Sequence type that represents lazily evaluated collections. Top-level functions for instantiating sequences and extension functions for sequences.

Utility functions for working with Java 8 streams.

System-related utility functions.

Functions for working with text and regular expressions.

Experimental API for representing Duration values and measuring time intervals.

Kotlin JavaScript wrappers for the WebGL API.

Kotlin JavaScript wrappers for the DOM API.

Kotlin JavaScript wrappers for the DOM CSS API.

Kotlin JavaScript wrappers for the DOM events API.

Kotlin JavaScript wrappers for the DOM parsing API.

Kotlin JavaScript wrappers for the DOM SVG API.

Kotlin JavaScript wrappers for the DOM URL API.

Kotlin JavaScript wrappers for the W3C fetch API.

Kotlin JavaScript wrappers for the W3C file API.

Kotlin JavaScript wrappers for the Web Notifications API.

Kotlin JavaScript wrappers for the Navigation Timing API.

Kotlin JavaScript wrappers for the Web Workers API.

Kotlin JavaScript wrappers for the XMLHttpRequest API.