Focus: Multiparadigm Programming Focus: Multiparadigm Programming Focus: Multiparadigm Programming

AT THE FIRST software engineering (SE) conference in 1968, Doug McIlroy introduced the concept of software components during his keynote speech, “Mass-Produced Software Components.”1 That components hold such an esteemed place in SE history should come as no surprise: componentization is a fundamental engineering principle. Top-down approaches decompose large systems into smaller parts—components—and bottom-up approaches compose smaller parts— components—into larger systems. Since 1968, components have played a role in both SE research and practice. For example, components have been an immanent part of software architecture from its early days.2 In 1998, the International Conference on Software Engineering introduced componentbased software engineering (CBSE) as a specific area within SE at the first workshop on CBSE, an event that eventually evolved into a series of symposia (http://cbse-conferences.org). In parallel, other events have addressed various CBSE-specific topics such as composability, predictability of functional and extrafunctional properties, modeling of component-based systems, reusability, deployment, software architecture and components, dynamic architecture, and middleware (see the sidebar “CBSE Terminology and Basic Concepts”). These topics have also become standard parts of many SE conferences (see the sidebar “CBSE Events”). Researchers and developers have taken notice: by March 2011, the Web of Science reported 1,546 publications containing both software and component in their titles; IEEE Xplore had 907 publications, and the ACM Digital Library had 1,254 titles. Clearly, this is a field experiencing a lot of growth.