Quoting from the ArcGIS Online site, “ArcGIS Online is a cloud-based, collaborative content management system for maps, apps, data, and other geographic information.”
They also have one of the best sets of high availability, fast, cached map tiles in the known world.
It was an easy decision to add support for their tile server into TrueNorth, and one that only took a few minutes to implement. Screenshot, as always of the Squamish area is below.
ArcGIS online, world topographic tile set