The premier cross-platform UI toolkits today are definitely: - QT in C++ - Electron in JS/TS But if you want to avoid those then you could try the Rust GUI e

The premier cross-platform UI toolkits today are definitely: - QT in C++ - Electron in JS/TS But if you want to avoid those then you could try the Rust GUI ecosystem. That gives you a few options: - gtk-rs which uses GTK but allows you to write in Rust rather than C - Dioxus which does use CSS layout (renders using Tauri webview under the hood) but allows you to write the code generating that in Rust. And the "backend" code is entirely Rust. - Iced which is pure Rust with it's layout system. But tbh it's still pretty immature and you'll be writing a lot of widgets yourself. You could also look at Flutter which works cross-platform and works completely within Dart.