Where is the Source Code? is a campaign to promote free, public distribution of OpenFOAM and software that links intimately to OpenFOAM. It is in response to a general dissatisfaction with the practice of making a modification to OpenFOAM, then promoting the benefits of the modification, without making that modification freely available to the public, often in order to sell it commercially. The campaign is simply to get people to ask “Where is the Source Code?” when modifications like this are promoted, for example after a conference presentation or in a response to a discussion on the Internet.