• SYMPHONY now has a preprocessor.
• The feasibility pump primal heuristic is implemented and activated by default.
• Reliability branching is now the default branching strategy.
• New statistics are now part of the default output.
• The granularity of the objective function value is set by calculating the GCD of the objective coefficients.
• Several changes in the management of valid inequalities, including quality checks and detection of duplicity.
• Minor changes in the management of the LP solver interface.
• Small bug-fixes and improvements.

SYMPHONY is an open-source solver for mixed-integer linear programs (MILPs) written in C. It can be used in three different main modes:

• As a callable library through either the native C interface or through the Osi.
• As an interactive solver using a command-line interface.
• As a framework to build customized solvers for specific problem classes.

This site is maintained by

Ted Ralphs
CORAL Laboratory
Department of Industrial and Systems Engineering
Lehigh University
Bethlehem, PA
(610)758-4784

tkralphs@lehigh.edu