The tutorial is ancient as computers go (1985), so it ignores cursor keys and other modern conveniences. Emacs supports these features but the tutorial doesn't take them into account. It's a good idea ...

What Is Doom Emacs? Doom Emacs is a custom Emacs distribution designed to streamline the text editor's default feature set, making it an approachable and powerful tool for both new and experienced ...

Emacs now displays the source code of the main routine, together with the GUD, locals, breakpoint and stack buffers, in a single frame. For the purposes of this tutorial, this arrangement is assumed.

An old joke is that Emacs is a text editor with an operating system included, given that its extensibility and customization often goes far beyond traditional text editors. Part of its well-earned … ...