Thermodynamics Properties calculation tool

[exergetic]

Hi everybody,
I'm looking for a free software (or web link) for calculation of thermodynamics properties (enthalpy,entropy,density,viscosity,etc.) of a wide range of substances.Does anyone have any suggestions about ?

Thanks in advance.

 

[MrMatt2532]

One of the better free resources:
http://webbook.nist.gov/chemistry/fluid/