In this paper we present the result of a comparative analysis of different programming languages and systems that claim the label object-oriented. In the second section the concepts of persistence, concurrency, composition, perspective, distribtuwn, location and mdility, communication, encapsulation, anronomy, and mzaatwn are presented as characteristics of physical objects. Crclssifrcations are used by people to organize their knowledge of physical objects. In the third section, we discuss the appearance of the concepts in programming languages and illustrate them through the difFerent investigated languages. In the last section we give a survey of a conceptual framework that gives the physical world metaphor its due and that will be supported in the TIE(Take It Easy)-system. * ECOOP'87 held in Paris, June 15-17.1987. 2 CH2S48-6/88/oooO/0002$01.00 0 1988 IEEE