CLU is an imperative and procedural programming language developed at MIT in the 1970s. It was designed with the aim of improving upon the shortcomings of existing languages, and of providing a clean and elegant language for systems programming.
CLU has a simple and clear syntax, and a small set of well-defined semantics. It is statically typed, with a type system that is based on the notion of subtypes. CLU programs are compiled to intermediate code, which is then interpreted by a virtual machine.
CLU is a very efficient language, and is well suited for a wide range of applications. It has been used in a variety of systems, including the operating system of the Space Shuttle, and the software for the Mars Pathfinder mission.