Montages/Gem-Mex: a meta visual programming generator

Last decade witnessed a disappointing lack in technology transfer from formal semantics to language design. Research in formal semantics has developed increasingly complex concepts and notation, at the expense of calculational clarity and applicability in the development of languages. Montages is a visual domain-specific formalism for specifying all the aspects of a programming language. It is intelligible to a broad range of people involved in the language life cycle, from design to programming language descriptions are fed to a rapid prototyping tool, called Gem-Mex, which generates a visual programming environment for the given language. Gem-Mex consists of a graphical front-end which allows a comfortable editing of the visual components of the specification. Starting from these visual descriptions the tool is able to generate in an automatic way high-quality documents, type-checkers, interpreters and a visual symbolic debugger. All these products form a powerful suite where the programmer can write, execute, animate and debug programs written in the specified language.