Thermodynamic properties in excel format

[ehilge]

Hey all, I'm looking for a version of steam/water thermodynamic properties for excel. I need it to be able to compute properties based on pressure and entropy. Something similar to the X Steam Tables (http://www.x-eng.com/XSteam_Excel.htm) would be awesome, but again, I need the ability to calculate information with pressure and entropy. Does anyone know where I could find such an item?
Thanks!

 

[Q_Goest]

NIST REFPROP:
http://www.nist.gov/srd/nist23.cfm

 

[ehilge]

Thanks, but I was hoping for something closer to the freeware/open source category. Any other ideas?