Aldwych is a general purpose programming language which we have developed in order to provide a mechanism for practical programming which can be thought of in an inherently concurrent way. We have described Aldwych elsewhere in terms of a translation to a concurrent logic language. However, it would be more accurate to describe it as translating to a simple operational language which, while able to be represented in a logic-programming like syntax, has lost much of the baggage associated with “logic programming”. This language is only a little more complex than foundational calculi such as the pi-calculus. Its key feature is that all variables are moded with a single producer, and some are linear allowing a reversal of polarity and hence interactive communication.