The U.S. Department of Energy Wind and Water Power Technologies Office launched an initiative to develop a Wave Energy Convertor Simulation (WEC-Sim) tool in the fall of 2012. As demonstrated through wind industry experience, WEC developers, who are typically start-ups with devices in the prototype phase, can accelerate development, analysis, and certification of system designs using a verified and validated suite of numerical modeling tools. Accordingly, to assist the nascent WEC industry, the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL) are developing an open-source WEC simulation tool that will be capable of modeling the dynamic response and power performance of WEC devices in operational wave climates. This paper will present the computational framework that will be used to develop the WEC-Sim code and will describe how online coding competitions will be used to assist in the development effort. The WEC-Sim validation and verification plan and external partnership opportunities will also be discussed.