ACOTSP: A software package of various ant colony optimization algorithms applied to the symmetric traveling salesman problem. This software package provides an implementation of various Ant Colony Optimization (ACO) algorithms applied to the symmetric Traveling Salesman Problem (TSP). The ACO algorithms implemented are Ant System, Elitist Ant System, MAX-MIN Ant System, Rank-based version of Ant System, Best-Worst Ant System, and Ant Colony System. Aim of the software: Provide an implementation of ACO algorithms for the symmetric TSP under one common framework. The implementation is reasonably high performing.