Invited Talk -- Composition by Anonymous Third Parties -- Session: Composition Contracts -- Defining Component Protocols with Service Composition: Illustration with the Kmelia Model -- Composite Contract Enforcement in Hierarchical Component Systems -- Towards a Unifying Theory for Choreography Conformance and Contract Compliance -- Session: Composition Design and Analysis -- A Process-Algebraic Approach to Workflow Specification and Refinement -- Generic Feature-Based Software Composition -- Composition Management Interfaces for a Predictable Assembly -- Path-Based Error Propagation Analysis in Composition of Software Services -- Session: Dynamic Composition -- Dynamically Adaptable Applications with iPOJO Service Components -- Dynamic Contextual Service Ranking -- Session: Short Papers -- Measuring Reactability of Persistent Computing Systems -- Requirements for Applying Aspect-Oriented Techniques in Web Service Composition Languages -- Synthesizing Communication Middleware from Explicit Connectors in Component Based Distributed Architectures -- Streamlining Feature-Oriented Designs -- Requirements for Reusable Aspect Deployment -- Session: Aspect-Oriented Programming -- Aspect-Oriented Programming: Selecting and Exposing Object Paths -- Debugging Aspect-Enabled Programs -- Unification of Static and Dynamic AOP for Evolution in Embedded Software Systems -- Session: Structural Composition -- Patterns of Component Evolution -- An Approach for Structural Pattern Composition -- Composite Connectors for Composing Software Components.

OnbehalfoftheOrganizingCommitteewearepleasedtopresenttheproceedings ofthe2007SymposiumonSoftwareComposition(SC2007).ThegoalofSC2007 wastobringtogethertheresearchandindustrialcommunitiesinordertoaddress the challenges of the component-based softwaredevelopment approach. SC 2007 was the sixth symposium on software composition in the SC series that seeks to develop a better understanding of how software components may be used to build and maintain large software systems. This LNCS volume contains the revised versions of the papers presented at SC 2007, which was held as a satellite event of the European Joint Conferences on Theory and Practice of Software (ETAPS) in Braga, Portugal, March 24-25, 2007. The symposium began with a keynote on "Composition by Anonymous Parties" by Farhad Arbab (CWI and Leiden University). The main program consisted of six technical sessions related to speci?c aspects of component-based software development. In response to the call for papers, we received 59 submissions from over 20 countries and 6 continents. Each paper was reviewed by at least three Program Committeemembers.TheentirereviewingprocesswassupportedbyMicrosoft's Conference Management Toolkit. In total, 15 submissions were accepted as full papers and 5 submissions were accepted as short papers.