"TypeScript is a typed superset of JavaScript that compiles to plain JavaScript"

• ES5
• ES6
• ES7 (async)
• commonjs, system, 2015 etc

• Optional static types
• Interfaces
• Abstract classes
• Generics
• Access modifiers
• Decorators

Types

• Prevent typos/bugs at compile time.
• Make safe refactoring possible.
• Help defining data models.
• Enable autocomplete in IDE's.

Pros/Cons

Scales

React DEMO