The objective of the Software Reuse program at Hewlett Packard is to institutionalize software reuse in selected business areas within the company. The program has a small staff of people at a central Corporate Engineering organization, and it works with several pilot projects in operating divisions. We are emphasizing reuse across a vertical span of domains from the application domain through low-level implementation domains. We are also focusing on external library, black box reuse of complete workproducts which have been explicitly designed for reuse. The design of software architectures for specific application domains and product families is key to a successful reuse program in a large company like HP.