Disclaimer: I’m an Atos employee and Atos are part owners of the Canopy solution. I also work on a client site using Documentum in an EMC OnDemand environment.
EMC have made quite a sales pitch around their OnDemand environments. The idea is that you can hand over the running of the environment to EMC in either a cloud or on premise solution. Using standard building blocks they can deploy environments quicker and manage them easier. In the Documentum world this is a pretty fantastic thing as bringing together the server and database teams and finding a consultant who has had time to test install the latest release is quite a feat.
Before WindowLogic were acquired by Atos I hadn’t even heard much about Canopy. It’s mainly a European based solution with data centers in Germany, France, Spain, UK and most likely many more. It turns out that they also host Documentum environments out of their German data center.