https://nxos.org/news/introducing-maui-shell/
The objective of Maui Shell is to deploy a convergent desktop shell with different form factors, from mobile phones and tablets to desktop computers. Maui Shell will adapt to various form factors, and there’s no need for multiple versions targeting different form factors.
Maui is a UI framework for KDE apps primarily aimed at smart phones or convergent applications. This is basically a whole desktop environment using Maui. Like a fork of KDE for smart phones and tablets.