RmlUI - a web-style GUI that can fit Irrlicht

[chronologicaldot]

Doing some browsing, I stumbled on RmlUI:
https://github.com/mikke89/RmlUi
It's basically a maintained fork of libRocket, which does UI web style (including animations). In libRocket (and presumably RmlUI), the UI data is rendered to a texture and vertice data that you then control how to render to your 3D system.
It's like the way ImGUI works I recall, but not as ugly.

Disclaimer: I have not tested it just yet, but it definitely looks easier to integrate and control than Qt (yuck) or GTK (which I succeeded in doing but didn't like).