Open source software makes the basic program instructions available for anyone to see and edit. An 'open source church,' likewise, is one in which the basic functions of mission and ministry are open to anyone. Members feel free to pursue their callings from God that are consistent with what God has called the congregation to be and do. But what does 'open source church' look like? In Open Source Church: Making Room for the Wisdom of All, Landon Whitsitt argues that Wikipedia, the encyclopedia that anyone can see and edit, might be the most instructive model available to help congregations develop leaders and structures that can meet the challenges presented by our changing world. Its success depends, he demonstrates, not on the views of select experts but on the collective wisdom of crowds. Then, turning to the work of James Surowiecki in The Wisdom of Crowds, he explores the idea that the body of Christ itself--when it is intentionally diverse, encourages independence of thought, values decentralization, and effectively captures and aggregates the group's collective wisdom--is an open source church. Together, these phenomena show us what an 'open source church' looks like. It is the body of Christ at its best.