Slate is a prototype-based object-oriented programming language based on
Self, CLOS, and Smalltalk. Slate syntax is intended to be as familiar as
possible to a Smalltalker, rather than engaging in divergent experiments in
that respect. Unlike the Smalltalk family, within Slate, methods can be
assigned to a signature of objects, instead of being installed on one
favored receiver. Slate has also many further expansions of the semantics
which interest advanced users.