Richard Tran Mills is a Principal Computational Engineer in the Mathematics and Computer Science Division at Argonne National Laboratory. His research has spanned high-performance scientific computing, geospatiotemporal data mining and machine learning, computational hydrology, and climate change science. He is one of the original developers of PFLOTRAN, an open-source code for massively parallel simulation of hydrologic flow and reactive transport problems, and is a core developer of PETSc, the Portable, Extensible Toolkit for Scientific Computation. He earned his Ph.D. in Computer Science in 2004 at the College of William and Mary, where he was a Department of Energy Computational Science Graduate Fellow. Prior to that, he studied geology and physics at the University of Tennessee, Knoxville as a Chancellor’s Scholar.