William Douglas Gropp is the director of the National Center for Supercomputing Applications (NCSA) and the Thomas M. Siebel Chair in the Department of Computer Science at the University of Illinois at Urbana–Champaign. He is also the founding Director of the Parallel Computing Institute. Gropp helped to create the Message Passing Interface, also known as MPI, and the Portable, Extensible Toolkit for Scientific Computation, also known as PETSc.