Since 1996 the USC Center for Software Engineering has been accumulating a large amount of software process experience through many real-client project software engineering practices. Through the application of the Experience Factory approach, we have collected and evolved this experience into an experience base (eBASE) which has been leveraged successfully for empirically based software process research. Through eBASE we have realized tangible benefits in automating, organizational learning, and strategic advantages for software engineering research. We share our rationale for creating and evolving eBASE, give examples of how the eBASE has been used in recent process research, discuss current limitations and challenges with eBASE, and what we hope to do achieve in the future with it.