Concorde is a computer code for the symmetric traveling salesman problem (TSP)
and some related network optimization problems. The code is written in the ANSI C programming language and it is available for academic research use; for other uses, contact William Cook for licensing options.
Concorde's TSP solver has been used to obtain the optimal solutions to all 110 of the TSPLIB instances; the largest having 85,900 cities.
The Concorde callable library includes over 700 functions permitting users to create specialized codes for TSP-like problems. All Concorde functions are thread-safe for programming in shared-memory parallel environments; the main TSP solver includes code for running over networks of UNIX workstations.
Concorde now supports the QSopt linear programming solver. Executable versions of concorde with qsopt for Linux and Solaris are now available
Hans Mittelmann has created a NEOS Server for Concorde, allowing users to solve TSP instances online.