Reliable knowledge of the thermophysical properties of pure compounds and their mixtures in the whole composition and a wide temperature and pressure range is a vital prerequisite for the computer aided synthesis, design and optimization of chemical processes. At the beginning of the development of thermodynamic models, the main interest was directed to the development of predictive g(E)-models for vapor-liquid equilibria (VLE) of subcritical compounds. Today group contribution equations of state are available which can also handle supercritical compounds, very asymmetric systems and even systems with strong electrolytes. These sophisticated models together with factual data banks (e.g. the Dortmund Data Bank) are powerful software tools for the reliable development of chemical processes and other applications of industrial interest. In this paper, the status of the different approaches and important applications of industrial interest using thermodynamic information derived from factual data banks or by using sophisticated predictive thermodynamic models will be presented. (C) 2003 Elsevier Science B.V. All rights reserved.