MCCs Software and Systems Engineering Productivity (SSEP) Project brings together emerging software engineering technology in architecture definition, analysis and generation, product family engineering, and rationale capture to enable organizations to achieve unprecedented levels of productivity and reuse. One of the central requirements for architecture-based product line development is the capability to efficiently and effectively navigate between related artifacts. This involves navigation both between product line artifacts and application artifacts, and between artifacts associated with successive development phases at each level. This navigation supports automated identification, selection and generation of artifacts, as well as manual development activities. This paper describes the Architecture Description Language (ADL) and toolset used by the SSEP project, and its support for linking and navigation in a product line development environment.