Biographical Sketch: Nicholas C Matsakis has been working in the z/OS for 23 years. He has been the Global Resource Serialization (GRS) design leader for 6 years. Nick started with IBM in 1984 in VM. In 1987, he joined MVS Recovery and Termination Manager (RTM) development. For 11 years he worked on the Cross System Coupling facility (XCF), the following extension (XES), and the Automatic Restart Manager (ARM) before becoming the OS/390 & z/OS EMEA Early Support Program technical manager and an advanced system support member based in Hursley, England. He continues to work in z/OS Base Control Program development in Poughkeepsie, New York.