This paper tells the story of the development of BETA: a programming language with just one abstraction mechanism, instead of one abstraction mechanism for each kind of program element (classes, types, procedures, functions, etc.). The paper explains how this single abstraction mechanism, the pattern, came about and how it was designed to be so powerful that it covered the other mechanisms.

In addition to describing the technical challenge of capturing all programming elements with just one abstraction mechanism, the paper also explains how the language was based upon a modeling approach, so that it could be used for analysis, design and implementation. It also illustrates how this modeling approach guided and settled the design of specific language concepts.

The paper compares the BETA programming language with other languages and explains how such a minimal language can still support …