Preface of the Workshop on Visual Formalisms for Patterns, VFfP'10

These proceedings contain selected and extended papers presented at VFfP’10, the secondInternational Workshop on Visual Formalisms for Patterns. The workshop was held as a satel-lite event of the 2010 IEEE Symposium on Visual Languages and Human-Centric Computing,VL/HCC 2010 at Madrid. This series of workshops brings together researchers interested in thedefinition, usage and analysis of patterns through visual formalisms, which couple the simplicityof traditional methods for pattern expression with solid foundations for pattern-based activities.Patterns are used in different disciplines as a way to record expert knowledge for problemsolving in specific areas. In Software Engineering, they are increasingly used for the definitionof software applications and frameworks, as well as in Model-Driven Engineering, to indicateparts of required architectures, drive code refactorings, or build model-to-model transformations.Their systematic use promotes quality, standardization, reusability and maintainability of soft-ware artefacts. The full realisation of their power is however hindered by the lack of a standardformalization of the notion of pattern. Presentations of patterns are typically given through natu-ral language to explain their motivation, context and consequences; programming code to showusages of the pattern; and diagrams to communicate their structure and behaviour.Several researchers have indicated the limitations of the current semi-formal devices for pat-tern definition – generally based on domain modelling languages, such as UML for design pat-terns, or Coloured Petri Nets for workflow – and research is active to propose rigorous for-malisms, methodologies and languages for pattern definition in specific domains, as well as topropose general models of patterns.The availability of formalisms will make common practices involving patterns, such as patterndiscovery, pattern enforcement, pattern-based refactoring, etc., simpler and amenable to automa-tion, and open new perspectives for pattern composition and analysis of pattern consequences.This workshop was conceived as a forum to communicate, discuss and advance in these direc-tions.The workshop technical contributions were carefully reviewed by three referees, and the pro-gram committee selected 7 long and 1 short papers, 6 of which were finally accepted for thesepost-proceedings. In addition, the technical programme included the keynote presentation “Aformal approach to patterns in MDE” by Prof. Yngve Lamo, from the Bergen University Col-lege (Norway), also included in these post-proceedings. The workshop was organized in threetechnical sessions (“Architectural Patterns and Refactorings”, “Patterns for User Interfaces andInteraction Design” and “Specification Patterns”) and finished with a discussion panel on thebenefits, limits and uses of pattern formalization.We would like to thank the members of the Program Committee and the secondary reviewersfor their excellent work – they are listed below – as well as the editorial team of ECEASST for their constant support.