Hi, Would there be any interest in an implementation of the IAPWS-95 in Boost? Here’s the reference: The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use. Authors: W. Wagner and A. Pruss J. Phys. Chem. Ref. Data, Vol. 31, No. 2, 2002, pages 387-535 For those with access to the paper, the code reproduces Table 6.6 (results agree to all published digits), as well as well significant parts of both Table 13.1 (vapor-liquid phase boundary properties as function of temperature) and Table 13.2 (properties of water in single-phase as function of temperature and density for pressures in range of 0.05 MPa to 1000 MPa). Also implemented are the full set of algorithms in Table 6.3, including pressure, enthalpy, entropy, sound speed, heat capacities. There’s also an algorithm for computing the thermal saturation properties (pressure, liquid and vapor densities), given the saturation temperature. At present the code has a required dependency on Boost.Units and is about 2k loc. If you're interested in this, feel free to reply or contact me directly. — Noel Belcourt [1] http://www.iapws.org