1. A computer-implemented method comprising: initiating, by a first application program of a first type that is executing on one or more configured computing systems, performing a first defined workflow using a workflow engine of the first application program, the performing of the first defined workflow including automatically performing one or more defined steps that are a subset of a plurality of defined steps of the first defined workflow, wherein the performing of the one or more defined steps includes sending an electronic communication to request indicated information from a second application program of a second type executing on at least one configured computing system, and wherein the second type of the second application program is distinct from the first type of the first application program; initiating, by the executing second application program in response to the electronic communication, performing multiple defined steps of a second defined workflow using a workflow engine of the second application program and sending one or more response electronic communications to the first application program that include the indicated information, wherein the performing of the multiple defined steps includes performing interactions with one or more users of the second application program; and under control of the executing first application program, receiving the indicated information from the one or more response electronic communications; and automatically performing additional defined steps of the plurality of defined steps to complete the performing of the first defined workflow, the performing of the additional defined steps being based at least in part on the received indicated information and including providing output available to one or more users of the first application program.