Engine/Zero is teh Aleph One replacement. Not backwards compatible. Won't run until you get a scenario too.

Cool stuff to do:

Press M for the fancy 3D map

Press O for an objective list

press T then type any of the following then press enter.

ScanVision 1

Zooming 1

and there's many more but I can't be bothered putting them here.

Oh well anyway E0 rocks.