IBM Parallel Sysplex® is a clustering technology that was designed to address specific client business objectives for IBM mainframe System z® servers. The nondisruptive addition of scalable processing capacity and improved application availability with respect to unplanned and planned outages were two key design objectives. This paper focuses on the evolving technology options that support the business objective of continuous availability. Key technology options are discussed relative to their importance to achieving continuous availability. Best practices for effectively using these technology options to improve availability, based on extensive client experiences, are recommended.