Release Notes: Optional method parameters were introduced.
Release Notes: Square brackets are no longer used for message passing. Messaging code was refactored.
Release Notes: Compact blocks were introduced.
Release Notes: Underscores are allowed in numeric literals.
Release Notes: A new "pass message" operator is introduced, represented by the colon. This changes the syntax for message chaining. The ":=" operator is also improved, supporting object instance variables.
Release Notes: A colon is no longer placed after a selector that invokes a variadic method, since the compiler knows when a method signature is variadic anyway. The tilde is now used instead of the colon to indicate unnamed methods and parameters.
Release Notes: Support was added for selector and protocol "literals." Object and class casts were made more safe and flexible.
Release Notes: A new syntax was added to chain messages concisely. The "<<" and ">>" object operators are now supported.
Release Notes: This is a pre-beta milestone. New features and bug fixes were added.