This is a Spectrum version of an experiment held in the middle 60's at the MIT Artificial Intelligence Laboratory by Joseph Weizenbaum. It's a language processor and it's meant to simulate a conversation between a human and the computer.
Obviously you can go very far with it, it's fairly simple and limited, but still holds interest because of the idea behind it. This version offers a few interactions which are sometimes almost normal, even thou they became rapidly weird and nonsensical. This random element made a lot of users to just use the game for laughs, by tinkering the program listing and changing a few lines and words.