Clean is a declarative, general-purpose programming language developed by Prof. Henri Bal and colleagues at the CWI, Amsterdam. It is based on the functional programming language Haskell and the logical programming language Prolog.
Clean has been designed with three main goals in mind:
1. To be a very concise language.
2. To have a simple and consistent semantics.
3. To be easy to learn.
In addition, Clean is a pure functional language, meaning that all computations are done by means of function calls. This makes it very easy to parallelize programs written in Clean.
The syntax of Clean is inspired by Haskell, but it is much simpler. For example, there are no type declarations in Clean. This makes programs shorter and easier to read.
Clean is a general-purpose language, but it is especially well suited for writing graphical user interfaces, database applications, and compilers.