The CoolProp.jl wrapper for the CoolProp fluids properties library has been around for a while, but now the package is registered and installable from the General repository. I’d like to highlight a new feature, which is support for Units, e.g. to get the enthalpy at 20°c and 50 % relative humidity for humid air:
using CoolProp using Unitful: °C, Pa HAPropsSI("H", "Tdb", 20°C, "RH", 0.5, "P", 101325Pa) 38622.83892391293 J kg⁻¹
Note that I am not involved with the project, all the hard work was done by the CoolProp developers, I just updated the package for modern Julia because I use it in my classes.