Numerical Recipes (Popularity: )
http://www.nr.com/ Complete free online versions of this standard textbook on computational methods, in the C, Fortran and Fortran-90 editions. PS/PDF. Software and C++ edition for sale.
Computational Thermodynamics (Popularity: )
http://www.calphad.com Calculation of phase diagrams with Thermo-Calc and DICTRA using the CALPHAD approach. General information about computational thermodynamics and computational kinetics and their industrial applications.