Chevy
Beepster
The "engine" term is used to describe the program that takes samples and spit them back out in a useable way to your DAW or whatever else you are outputting it to.
So.... can you insert it as a soft synth like Superior Drummer?
If it's a VSTi then yes. I know that's probably confusing as well but VSTi means it can be used inside a "host" DAW (like AD2, Superior Drummer, BFD, etc).
The only reason I am noting the difference is because I believe technically hardware drum units can be described as having an internal engine and there are probably standalone drum programs that cannot be inserted into a DAW (like ones specifically for live use but I don't know for sure).
Any drum program that can be inserted into a DAW project will say so in it's product details. Probably really hard (if not impossible) to find a drum program that CAN'T be used in a DAW these days.
Cheers.