Flutter

Flutter is a UI framework developed by Google for building applications that compile to native code on Android, iOS, web, Windows, macOS, and Linux from a single Dart codebase. Google released the first stable version in December 2018. Unlike frameworks that render through platform webviews, Flutter draws every pixel directly using its own rendering engine.

The current stable release is Flutter 3.29. The framework uses a widget composition model — the entire UI is a tree of immutable widget descriptions that Flutter diffs and re-renders efficiently. The rendering pipeline originally used Skia and is transitioning to Impeller, a newer engine designed to eliminate shader compilation jank. Flutter ships with Material 3 and Cupertino widget sets for platform-appropriate styling.

The official documentation includes codelabs, cookbook recipes, and API references. The source code is on GitHub under the BSD license.