The subset of JavaScript 2 (ActionScript 3, ECMAScript 4) has been carefully chosen to contain the language features that

• address real-world problems,
• ease development,
• add to the strengths of JavaScript, and
• can be translated to efficient, debuggable JavaScript 1.x.

The currently supported language features are:

• classes (inheritance)
• packages
• static members
• private members
• type annotations

All details are described in the Jangaroo language reference.