1. A non-transitory computer-readable medium whose contents configure a computing device to act as an intermediary to facilitate performance by task performers of tasks submitted by task requesters, by performing a method comprising: receiving, by the configured computing device, information from an executing program of a task requester about a task that is available to be performed, the information received via a defined programmatic application program interface and indicating one or more criteria for satisfactory performance of the task; providing, by the configured computing device, information about the task to one or more human task performers who are able to satisfactorily perform the task based on the indicated criteria; and after receiving results for the available task based on performance of the task by one or more of the human task performers to whom the information about the task was provided, supplying, by the configured computing device, the received results via the defined programmatic interface to a program of the task requester.