In both cases, when it comes to overlaying polylines, you own the data you're overlaying, storing it on your own server, and commercial use of the base map/APIs is allowed. And google does not permit any copying of their maps whatsoever (this is the big 'open' difference with OpenStreetMap actually) Most web developers are blissfully unaware of this. Google by contrast have some fairly aggressive terms of use on their API, granting use of your data to them. OpenStreetMap generally doesn't attach any conditions to data overlaid upon it, unless you are copying ('deriving') a substantial chunk of geodata by tracing from the background map, in which case it must be ODbL licensed. Very basic example of drawing a polyline. My personal recommendation for this would be to start with leafletJS and OpenStreetMap. It is open source though, so could be customised or.Дevelop something like this yourself from scratch using a web mapping API You're asking about APIs so I assume this is not a crazy suggestion. That should give you some idea of what's possible in terms of editable polylines, but I don't think it will give you the naunced permissions model you want, or the feature 'identify if an address is within a defined territory'. There's a nice tool called uMap which lets you create a map with polylines, in a very easy point and click way, and then open this to a group of people to make edits. A web browser can start to get a bit overloaded if you present too much map data as a vector overlay, but you can go quite a long way with this kind of approach. You might run into problems with this approach if you have a very large number of boundaries or the boundary polygons are very detailed, with a very large number of corners. It depends how much data there is but I think you should probably tackle this with polylines overlaid upon a basemap. There's several ways you might set up a system for a team of people to be able to add an adjust 'boundaries'.

Wikimapia maps of 10 years ago