You may make use of the Licensed Work, provided that
you may not use the Licensed Work for a Document
Service.
A “Document Service” is a commercial offering that
allows third parties (other than your employees and
contractors) to access the functionality of the
Licensed Work by creating teams and documents
controlled by such third parties.That language is the sort of seemingly straightforward sounding language that can and does get litigated to death, and I wouldn't blame a corporate lawyer for advising his or her client to steer clear.
What I do agree with, is that any careful corporate lawyer would have a good look at this license and check whether there are any courts that have ever looked at this license to see how battle tested it is. Speaking as a lawyer, what I would see as an edge case that might be problematic is if a competitor of Outline that uses its completely self-built tech stack to provide a competing service as outlined in that clause would use Outline internally as a knowledge base. But I mean that‘d be absurd.
// addendum Personally, I think it would be cool if Outline at some point removed that clause, once it has built sufficient moat around its commodity services.
I can't tell you how many telemedicine (aka, video conferencing) services use Zoom, Google, or GTM as their teleconferencing solution when speaking with prospective clients.
I've literally only had one that was actually using the televideo software they were pitching me as the televideo platform for our demo call. One out of many.