Racket espouses the view that full-fledged problem solving almost always calls for language design. In support of this view, it implements a notion of linguistic reuse, which allows programmers to rapidly develop and deploy new programming languages. Together with DrRacket, its IDE, the Racket ecosystem thus makes up a true language workbench. This paper demonstrates Racket’s capabilities with an implementation of the 2016 Language Workbench Challenge. Building on a concise implementation of MiniJava, it shows how it is easy it is to add new notation, constrain constructs, and create IDE tools.