17. A computer-implemented system that implements collaborative editing of a walkthrough, including: a processor and memory, the memory holding code that implements: for each of a plurality of contributing authors, create an editable version of a publisher's base walkthrough of a live application and stores the contributing author's walkthrough version; wherein the publisher's base and the contributing authors' walkthrough versions implement a series of activity steps that are configurable to be presented on an instruction layer that visually overlays the live application, flow of control among the activity steps is implemented by program code that is processed to coordinate presentation of the activity steps on the instruction layer that overlays a display generated by the live application, whereby performance by a user in accordance with instructions presented in the activity steps on the instruction layer causes interaction with the live application and advancing through the series of activity steps; receive and store edited contributing authors' walkthrough versions; transmit, towards the publisher, data for display that elicits selection among the plurality of contributing authors' walkthrough versions; receive the publisher's selection of at least one contributing author's walkthrough version to use to update the publisher's base walkthrough; transmit modifiable data for display that includes step facsimiles and an editable rendition of the activity steps of the selected contributing author's walkthrough version; and receive publisher's acceptance of an edited activity step in the selected contributing author's version of the walkthrough and apply at least the publisher accepted activity step to the live application to update the step facsimiles.
17. A computer-implemented system that implements collaborative editing of a walkthrough, including: a processor and memory, the memory holding code that implements: for each of a plurality of contributing authors, create an editable version of a publisher's base walkthrough of a live application and stores the contributing author's walkthrough version; wherein the publisher's base and the contributing authors' walkthrough versions implement a series of activity steps that are configurable to be presented on an instruction layer that visually overlays the live application, flow of control among the activity steps is implemented by program code that is processed to coordinate presentation of the activity steps on the instruction layer that overlays a display generated by the live application, whereby performance by a user in accordance with instructions presented in the activity steps on the instruction layer causes interaction with the live application and advancing through the series of activity steps; receive and store edited contributing authors' walkthrough versions; transmit, towards the publisher, data for display that elicits selection among the plurality of contributing authors' walkthrough versions; receive the publisher's selection of at least one contributing author's walkthrough version to use to update the publisher's base walkthrough; transmit modifiable data for display that includes step facsimiles and an editable rendition of the activity steps of the selected contributing author's walkthrough version; and receive publisher's acceptance of an edited activity step in the selected contributing author's version of the walkthrough and apply at least the publisher accepted activity step to the live application to update the step facsimiles. 20. The system of claim 17 , wherein the live application is a cloud-based software as a service offering and the interactions with the live application exercise controls on app panels of the live application.