XA

XA is a optimizer for solving linear, and mixed-integer problems developed by Sunset Software Technology http://www.sunsetsoft.com/.  XA contains a modified primal simplex algorithm, a dual simplex algorithm, and an interior point barrier algorithm.  For problems with integer variables, XA uses a branch and bound algorithm (with cuts) and supports specially ordered set variables SOS1, SOS2 as well as semi-continuous and semi-integer variables.  XA solves LP, MIP and RMIP model types.  The solver manual for XA is on XA.pdf.

An additional variant of XA exists.