Gosu is a pragmatic programming language for the JVM. It has been designed with Java developers in mind by providing a set of features that allow them to be more productive without sacrificing the benefits of Java’s simple syntax and type-safety. Gosu is an object oriented language with a sprinkle of functional programming features.

Gosu features:

• Open Type System
• Advanced type inference
• Program files (scripts containing statements, functions, and classes at the same level)
• Structural typing (similar TypeScript’s interfaces)
• Extension methods (aka enhancements)
• Java interoperability
• Lambda expressions
• Classes/Interfaces/Enums
• Generics (reified, covariant type parameters and no wildcards)
• Composition (with the delegate keyword)
• Properties
• Null Safety (supports operator ?. etc.)
• Named Arguments and Default Parameter Values
• A powerful for each statement with user-defined intervals types
• Member Literals
• Object Initializers
• Classpath Statement and Shebang (useful when you use Gosu as a scripting language)
• ...and more