Centro di Ricerca e Formazione per l'Ottimizzazione su Reti: Network flow, B&B for ATSP

Andrew Goldberg's Network Optimization Library: Network flow, assignment, Shortest Paths

David Pisinger's optimization codes: Knapsack, Bin packing, Container loading

Martello, Toth: Knapsack problems: Knapsack FORTRAN codes

COIN-OR: Various codes.

Stony Brook: Repository of algorithms

JEA: Journal of experimental algorithms code repository