Under this NSF CAREER project, we are developing representations and algorithms to manage large digital libraries of complex engineering knowledge. The algorithms and data structures we are creating will integrate knowledge-bases of geometric information with systems for case-based reasoning and digital information retrieval. The research in this highly interdisciplinary project bridges several important fields: geometric reasoning, case-based reasoning, and digital libraries; it draws on the challenges presented by real-world problems from the domain of solid modeling and ComputerAided Design (CAD) for engineering and manufacturing. This paper gives a brief overview of our progress during the 1998-1999 academic year.