The objective of this issue was to provide an integrated forum for the presentation of research and the exchange of ideas and experiences in the topics concerned with proofs, concurrency and object-oriented programming (specification, proof development, etc...). The selected papers address some of these topics focusing on problems such as: to use the actor model as a faithful basis for rigorously designing open distributed systems, to use linear logic for the specification of advanced concepts of concurrent object-oriented programming or to develop techniques for proving behavioral correctness of concurrent based-on objects systems.