Release 2.0 introduces full source-level debugging of

optimised code, adaptive optimisation to shorten compile

pauses, lightweight threads within Self, support for

dynamically linking foreign functions, changing programs

within Self and the ability to run the experimental Self

graphical browser under OpenWindows. Designed for

expressive power and malleability, Self combines a pure,

prototype-based object model with uniform access to state

and behaviour. Unlike other languages, Self allows objects to

inherit state and to change their patterns of inheritance

dynamically. Self's customising compiler can generate very

efficient code compared to other dynamically-typed

object-oriented languages.