REFPROP is authored, maintained and distributed by the National Institute of Standards and Technology (NIST).
AmsterCHEM has developed REFPROP CAPE-OPEN as a CAPE-OPEN Property Package Manager which lets you create CAPE-OPEN Property Packages out of REFPROP and use them in any PME with a CAPE-OPEN thermodynamic socket.
See example of use of such a feature in gPROMS within the modelling of a pressure swing absorber at University of Porto, Portugal.