Abstract: This presentation will introduce work in the U.S. Exascale Computing Project, where a varied suite of scientific applications builds on programming models and runtimes, math libraries, data and visualization packages, and development tools that comprise the Extreme-scale Scientific Software Stack (E4S). The presentation will introduce crosscutting strategies that are increasing developer productivity and software sustainability, thereby mitigating technical risks by building a firmer foundation for reproducible, sustainable science. The presentation will also mention complementary community efforts and opportunities for involvement.