The 2009 Symposium on Component-Based Software Engineering (CBSE 2009) was the 12thin a series
ofsuccessful eventsthat havegrowninto the main forum for industrial and academic experts to
discuss component technology. Component-based software engineering (CBSE) has emerged as the
under- ing technology for the assembly of ?exible software systems. In essence CBSE is about
composing computational building blocks to construct larger building blocks that ful?ll client
needs. Most software engineers are involved in some form of component-based development.
Nonetheless the implications of CBSE adoption are wide-reaching and its challenges grow in
tandem with its uptake continuing to inspire our scienti?c speculation. Component-based
development necessarily involves elements of software - chitecture modular software design
software veri?cation testing con?guration and deployment. This year's submissions represent a
cross-section of CBSE - search that touches upon all these aspects. The theoretical foundations
of c- ponent speci?cation composition analysis and veri?cation continue to pose research
challenges. What exactly constitutes an adequate semantics for c- munication and composition so
that bigger things can be built from smaller things? How can formal approaches facilitate
predictable assembly through b- ter analysis? We have grouped the proceedings into two
sub-themes that deal with these issues: component models and communication and composition. At
the same time the world is changing.
