This article describes the design and development of a design repository software system. This system is a prototype implementation intended to demonstrate the role of design repositories as part of a vision for the next generation of product development software systems. This research involves not only the creation of a prototype software system, but is part of a broader effort that also includes the development of a core product knowledge representation and that seeks to address terminological and semantic issues associated with computer-aided product development. This article focuses on the interfaces that have been developed to support authoring and navigation of the product models stored in design repositories as well as the software architecture and associated rationale that provide the framework on which the system is built.