This book constitutes the proceedings of the 18th International Conference on Foundations of
Software Science and Computation Structures FOSSACS 2015 held in London UK in April 2015
as part of the European Joint Conferences on Theory and Practice of Software ETAPS 2015. The
28 full papers presented in this volume were carefully reviewed and selected from 93
submissions. They are organized in topical sections named: semantics of programming languages
categorical models and logics concurrent probabilistic and timed systems automata games
verification logical aspects of computational complexity and type theory proof theory and
implicit computational complexity. The book also contains one full paper invited talk.
