An open, shared knowledge commons for N-of-one cancer researchers. (a) The closed model of knowledge management. Nearly all corporations and even most academic and non-profit groups tend by default to set up closed systems in which users of the information have little incentive or mechanism to feed information back into a community resource. (b) The open knowledge model. A knowledge commons enables the development of a diverse community of applications targeted at different user groups. All users have the incentive to feed information back to the commons and apps can provide mechanisms to do so.