CoolProp is a thermophysical property database and wrappers for a selection of programming environments

It offers similar functionality to REFPROP, but CoolProp is open-source and free, with flexible licensing terms.  Commercial - ok! Academic? - ok!

It was originally developed by Ian Bell, currently a post-doc at the University of Liege, in Liege, Belgium.

The development docs for the v5 release are at http://www.coolprop.dreamhosters.com:8010/sphinx/ 

The development binaries for each platform are at http://www.coolprop.dreamhosters.com:8010/binaries/.

Please, if there are any issues of any kind, file an issue at https://github.com/CoolProp/CoolProp/issues

Also, check out our FAQ: https://github.com/CoolProp/CoolProp/blob/master/FAQ.md