The BETA programming language has been developed in the Scandinavian tradition for object-orientation based on Simula. In this tradition, support for modeling and design have been important design goals for programming language design. There has thus been two accompanying design criteria for BETA. BETA should be a useful tool for modeling concepts and phenomena from an application domain, and it should be an efficient tool for implementing such models. To support modeling and design, a conceptual framework was develop together with the BETA language. The conceptual framework is a set of conceptual means for understanding knowledge abuout the real world. It includes means such as concepts and phenomena, identification of objects, identification of classes, classification, generalization/specialization, multiple classification, refence- and part-of-composition, etc. In this paper we concentrate on presentin the BETA language.