I like egui a lot. It’s very simple conceptually: at any point you can ask how much room is available to render in, and you can draw anything immediately at that point, relative to that point, or absolutely anywhere.

The layout system maintains a cursor of where it’s currently drawing, and moves left to right, up down, etc depending on the layout you’re using. That’s all there is to it really.

Using this I have been able to build some powerful controls. The one that impressed me the most about egui was egui-nav, where I built an entire ios-style navigation control without too much effort.