The goal of the Yeti is to have a clean and minimal expressive language on the JVM that allows functional style programming, has static type inference and interfaces well with Java code.

Some of the features:

• Type inference using the Hindley-Milner algorithm. The types are statically inferred at compile time without a need for explicit type declarations.
• Polymorphic structure and variant types. Using those resembles duck typing from the dynamic languages - for example, when a value is used as a structure having a field foo, which gives string value, then any structure with string field foo will be good enough.
• Property fields in structures (access goes through function calls).
• Lazy lists
• Pattern matching on values
• Comfortable string regex support
• Easy to call existing Java code
• Interactive REPL environment for experimenting
• Compiles directly to Java bytecode