I am a strong believer in the potential of open-source software to accelerate scientific research by enabling rapid adoption of new methods and approaches and reproducibility of simulations and analyses that others have conducted. I am one of the original developers (I began initial implementation of the flow modules during my fellowship practicum at Los Alamos in 2003) of the open-source, massively parallel hydrologic flow and reactive transport code PFLOTRAN, and, for many years, I have been a user and occasional (now full-time) contributor to development of the Portable, Extensible Toolkit for Scientific Computation (PETSc), which provides the underlying computational framework for PFLOTRAN and many other scientific simulation codes. I also serve as a topical editor for Geoscientific Model Development, an open-access journal that promotes open publication of source code and data for geoscientific models in an archival form that ensures scientific reproducibility.