[sklogic]

Yes, to my taste this language is nowhere near a DSL it should have been, but still, there is a significant portion of VM semantics that is hard to implement on top of an existing VM.

The article outlines it as follows:

"1) Sensor readings are collected and stored in the BVM; 2) Incoming messages are collected and processed by the BVM; 3) A portion of the Buzz script is executed; 4) The messages in the BVM output queue are sent (as many as possible, according to the available payload size; see Sec. IV); 5) Actuator values are collected from the BVM state and applied."

I.e., it looks like a complex synchronisation semantics which runs underneath any language layers and therefore hard to implement anywhere higher than in the VM.