A thermodynamic model is presented, by which the vapor-liquid equilibria and the phase properties (enthalpy, entropy, heat capacity, etc.) can be predicted for a wide variety of systems, including polar and gaseous components, and conditions. The method is based on a cubic equation of state with the Huron-Vidal mixing rules and a table of group contributions for the estimation of the mixture parameters. Work has started recently at Hyprotech and the table of group contributions is under development. Some preliminary results in the prediction of VLE of alkane-alkanol-ether systems are presented.