Geophysical inverse problems are used to estimate models of the subsurface from a finite number of data collected over the earth. SimPEG (Simulation and Parameter Estimation in Geophysics, http://simpeg.xyz) is a collaborative effort to develop an open source framework for solving geophysical simulation and inversion problems, including electromagnetics, vadose zone flow, and potential fields, in a consistent manner. The goal in the development of SimPEG is to support a community of researchers with well-tested, extensible tools, and encourage transparency and reproducibility both of the SimPEG software and the geoscientific research it is applied to. Using an example from applied electromagnetics: monitoring an injection (such as a hydraulic fracturing) from a steel cased well, I will provide an overview of the framework and discuss some of the strategies we are using to promote collaboration. I will also discuss how we have re-purposed the numerical tools in SimPEG to build web-based interactive simulations for students to explore fundamental concepts in geophysics (http://geosci.xyz).