Dart is a client-optimized language for fast apps on any platform
Supported by Google

Dart is free and open source  

for UI
Develop with a programming language specialized around the needs of user interface creation
Make changes iteratively: use hot reload to see the result instantly in your running app
Fast on all
Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web

Try Dart in your browser

Want more practice? Try a codelab. Or download Dart.