John Mellor-Crummey is a Professor of Computer Science at Rice University in Houston, TX. His research focuses on software technology for high-performance parallel computing. His current research is focused on research and development of tools for measurement and analysis of the performance of applications on scalable parallel platforms, including GPU-accelerated exascale systems. The HPCToolkit Performance Tools project is the primary product of that research. His past work has included compilers and runtime systems for parallel computing, scalable synchronization algorithms for shared-memory multiprocessors, execution replay of parallel programs, data race detection, and techniques for network performance analysis and optimization. Mellor-Crummey co-led development of the OMPT tools interface for OpenMP 5. He is a co-recipient of the 2006 Dijkstra Prize in Distributed Computing and a Fellow of the ACM.