Preface; J.Woodcock.- Concurrent Interaction Games; S.Abramsky.- Program Optimisation Naturally; R.Bird, J.Gibbons & G.Jones.- The Binary Euclidean Algorithm; R.P.Brent.- Domain Modelling; D.Bjorner.- Communicating Parallel Processes; S.Brookes.- Computing with Shapes; S.Cameron.- Predicate Transformers for Competition; K.M.Chandy & M.Charpentier.- A Note on Monitor Versions; O-J.Dahl.- A Formula is Worth a Thousand Pictures; E.W.Dijkstra.- Linking Higher Order Logic to Binary Decision Diagrams; M.Gordon.- Substitution of Equals for Equals; D.Gries & F.B.Schneider.- Advanced Features of the Duration Calculus; H.Jifeng & X.Qiwen.- Formalism and the Variable; E.C.R.Hehner.- The Real World; Michael Jackson.- Compositionality, Inference and Concurrency; C.B.Jones.- Dancing Links; D.E.Knuth.- The Transputer Revised; D.May.- Principles of Language Design and Evolution; B.Meyer.- Computing and Communication What's the Difference?; R.Milner.- Generating-functions of Interconnection Networks; J.Misra.- Probably Hoare? Hoare Probably!; C.Morgan, A.McIver & J.W.Sanders.- Distributed Computing : Opportunity, Challenge or Misfortune?; R.M.Needham.- A Linear-time Algorithm for Verifying MLL Proof Nets via Essential Nets; A.S.Murawski & C.-H.L.Ong.- Intuitionistic Reasoning about Shared Mutable Data Structure; J.C.Reynolds.- The Successes and Failures of Behavioural Models; A.W.Roscoe, G.M.Reed & R.Forster.- The Algebra of Searching; M.Spivey & S.Seres.- Modeless Structure Editing; B.Sufrin & O.de Moor.- A Chaos-free Failures-divergences Semantics with Applications to Verification; A.Valmari.- Records, Modules, Objects, Classes, Components; N.Wirth.- Abstract Data Types and Processes; J.Woodcock, J.Davies & C.Bolton.- A Higher-order Duration Calculus; Z.Chaochen, D.P.Guelev & Z.Naijun.