- Type Inference
- Builtin Literals for lists, hashes, arrays, regular expressions and timespans
- Slicing
- String Interpolation
- Statement Modifiers
- Syntactic Attributes
- Syntactic Macros
- Generators
- First Class Functions
- Closures
- Callable Types
- Duck Typing
- Extensible Compilation Pipeline
- User-defined Value Types
- Interactive Interpreter
See the Boo Language Guide for a more complete reference, as well as the Tutorials and Cookbook.