Slint (https://slint.dev) is an open source declarative GUI toolkit to create elegant, modern, and native GUI for embedded, desktop, and web applications. One of the USPs of Slint is that it supports multiple programming languages such as C++, Rust, and JavaScript. Recently, one of the Slint community members added support for C#. Check out Matheus' YouTube video where he walks through the demo applications -- https://www.youtube.com/watch?v=EwLFhk5RUwE