What is the Introjuicer?

Hey! Juce newbie here. I’ve just downloaded Martin Robinson’s “Getting Started with Juce” textbook. In it, rather than using the Projuicer (which I seem to have downloaded), he uses the Introjuicer to build his app. He says the Introjuicer .slx can be found at juce/extras/introjuicer. When I go to the extras folder, however, the introjuicer folder does not exist. Am I looking for the wrong thing, or has the introjuicer been replaced by the projuicer?

Introjucer was replaced by the Projucer.

Yeah, that’s from Juce 3.x and earlier