Yes, it's a Dornier, I believe. It was a contemporary of the experimental Bell VTOL aircraft, which itself was a progenitor of the V-22 Osprey. I believe the wingtip pods contained the vertical-lift jets, and the pods in the middle of the wing had the forward-propulsion engines.
From the experience gained with the Dornier Do 31E, the Dornier Do 231 was proposed in response to a German Federal government requirement for a civil and military V/STOL transport. The winning design from five others, it was expected to be flying by the late 1970s. Not to be.
Some nice pics. I would be worried about the wing stress on liftoff with the engins outboard of the forward flight ones. But that is just my impression without any test numbers.