Whereas for myself in my own free time I bias more to the ruthlessly pragmatic, which often means the simplest or easiest solution, so I can move on to the next thing.
Random pick from those:
- many many years ago I once wrote a Terminal-like UI widget for Java AWT/Swing apps. This was in the very very early days of Java. To scratch my own itch. It gave me a way in my Swing/AWT desktop apps to embed a console/REPL-like widget (which could be kept invisible/inactive by default, then only appear when a special key pressed) to let me issue CLI-like commands in-app, for example for cheat codes or dev testing or to provide extra features to advanced users. It provided an API for registering comands and their handlers. Had built-in commands like "help" and to repeat the last command, etc. So my Java GUI apps could have the best of both worlds: the "friendliness" of the GUI and the power and conciseness of a terminal workflow. Super simple. Only ever used in a few of my hobby apps (and a few games I considered selling then.)
I named it, originally, in private, SwingShell. Then renamed it to Grio, because that had more personality. (Obligatory Pulp Fiction reference.) I even devised my own little theme song for it. Okay more of a tune. A melodic catchphrase. Why? Here let me show you my nerd license. Hold still, please. This will only take a second.