Combinatorial Optimization

This special issue of Mathematical Programming B is dedicated to the second Interna- tional Symposium on Combinatorial Optimization (ISCO 2012), which took place in Athens, University of Economics and Business (AUEB), on April 19-21, 2012. ISCO 2012 was preceded by the Spring School on "Mathematical Programming and Design of Approximation Algorithms" given by David Shmoys and David Williamson. This edition of ISCO was the second of a series of biennial conferences on combinatorial optimization with its first venue held in Hammamet, Tunisia in March 2010. ISCO is intended to be a forum for the exchange of recent scientific developments and for the discussion of new trends. The scope of the conference includes all aspects of combina- torial optimization ranging from mathematical foundations and theory of algorithms to computational studies and practical applications.