In Pursuit of the Traveling Salesman: Mathematics and the Limits of Computation, available for $14.27 @ Amazon. News items can be found on the book's Facebook Page. Concorde TSP app for the iPhone and iPad avaiable on the Apple App Store. It's free!

The Traveling Salesman Problem: A Computational Study by Applegate, Bixby, Chvatal, and Cook. Description of the techniques we use to compute lower bounds on the lengths of all TSP tours.

Optimal solution for visiting all 24,978 cities in Sweden. Tour has length approximately 72,500 kilometers. The TSP was featured in a contest run by Proctor and Gamble in 1962. The challenge problem had 33 cities.

A graphical user interface available for Concorde on Windows' platforms. The Concorde TSP solver is used in a genome sequencing package from the National Institutes of Health.

A collection of 25 TSP challenge problems consisting of cities in Argentina through Zimbabwe. Pages describing some of the history of the TSP as a mathematical and computational challenge.