I don't know how much it shares w/ OLE compound documents, but OLE for Process Control (OPC, now retroactively renamed to "Open Platform Communications") is very common in multi-vendor SCADA environments.
It has a common ancestry, but OPC moved on. They are now using OPC-UA. And the usage is totally different. In OPC you do not imbed one app in another, it is a standardised protocol to get data from DCS/SCADA. But they did use DCOM up until OPC V 3.
