On behalf of the Organizing Committee I am pleased to present the proceedings of the 2005 Symposium on Component-Based Software Engineering (CBSE). CBSE is concerned with the development of software-intensive systems from reusable parts (components), the development of reusable parts, and system maintenance and improvement by means of component replacement and c- tomization. CBSE 2005, Software Components at Work, was the eighth in a series of events that promote a science and technology foundation for achieving predictable quality in software systems through the use of software component...