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type *credits (in game)

Or in the editor, click the MENU button and the version is at the bottom of the pop up menu.

There is an inbuilt CREDITS command. I normally override this to give something a bit more user-friendly and to provide any extra credits needed. As, Adventuron said, you can still see the default sytem command using *CREDITS.

I don't think you can see it programmatically, but you don't really need to, as you know what version you're using during development and this is the version that's embedded with the game when it's compiled.