A custom Unity Inspector for building Roguelike levels, using UIToolkit
I have one custom Inspector that lets you type in raw text and it builds a Roguelike level (creates all the GameObjects, MonoBehaviours, etc) as you type.
This one then reads in the results of that, renders it using UIToolkit, and interactively lets you click on any ASCII character to create GameObjects on top of that cell.
Here you can see me adding some coins, adding a weapon, adding some armour -- I'm creating a treasure-room for the player to find after defeating a boss mob.