lp_solve is a free linear (integer) programming solver. The solver is a callable library written in ANSI C.
lp_solve is a free (see LGPL for the GNU lesser general public license) linear (integer) programming solver based on the revised simplex method and the Branch-and-bound method for the integers.
lp_solve solves pure linear, (mixed) integer/binary, semi-continuous and special ordered sets (SOS) models.
It can also be called as a library from different languages like C, VB, .NET, Delphi, Excel, Java, ... It can also be called from AMPL, MATLAB, O-Matrix, Scilab, Octave, R via a driver program. lp_solve is written in ANSI C and can be compiled on many different platforms like linux and WINDOWS.
More details, including an FAQ, and an intro to lp_solve can be found here.
