BETA has powerful abstraction mechanisms for supporting identification of objects, classification and composition. It is well known that it is not possible to obtain all type checking at compile time without sacrificing the expressiveness of the language. BETA has an optimum balance between compiletime type checking and runtime type checking. FREE Version Objective-C C with Smaltalk entensions. Prototypes combine inheritance and instantiation to provide a framework that is simpler and more flexible than most object-oriented languages.
Slots unite variables and procedures into a single construct.
This permits the inheritance hierarchy to take over the function of lexical scoping in conventional languages. Finally, because Self does not distinguish state from behavior, it narrows the gaps between ordinary objects, procedures, and closures. NewtonScript is garbage collected with an object model based on prototype inheritance. Currently only available on the Newton PDAs. It is designed to be simple enough that many programmers can achieve fluency in the language.