In these proceedings of the May 2005 workshop, participants present their research in this software engineering and maintenance field, including case studies. Topics include concerns and concepts, theories of program comprehension, framework understanding, empirical studies, tool demonstrations, code understanding and refactoring, dynamic analysis, clustering and components, and software visualization. The proceeding as also include the keynote, materials on the working sessions, and the short papers. Annotation ©2005 Book News, Inc., Portland, OR (booknews.com)