The goal of the project was to develop the next version of the fluid property sublibrary of the Modelica Standard Library (MSL). The currently available fluids will be kept, but there is a need to extend the MSL with properties for multi-phase multi-component fluids. Most fluid properties available today are in specialised programs written in C or Fortran, like MultiFlash by InfoChem or FluidProp by TU Delft, or they are part of process engineering simulators. That makes it necessary to include external interfaces to access these properties from Modelica. CAPE-OPEN is the best known interface with many properties available and is a natural first choice. On the other hand it is necessary to support encapsulated models as standardized in the FMI-standard, which is also maintained by the Modelica Association. Therefore, a native C/C++/Fortran interface was also developed in this project. The results were going to be integrated into the Modelica Standard Library.