The design here is very similar to Slint (https://github.com/slint-ui/slint), which I work on: both are implemented in Rust, with a declarative UI DSL and its own compiler, logic in a host language (Rust, C++, JS or Python for Slint), pure reactive expressions, and tooling that lets agents inspect and drive the app.
One difference is that Slint is more mature: it's been 1.x with a stable API since 2023
Not really. Slint also has a royalty-free license, so you can make proprietary applications for free. So it’s GPL for open-source apps (including if your own code is MIT/Apache as they are compatible), and royalty-free for proprietary apps. Is that not enough?
One difference is that Slint is more mature: it's been 1.x with a stable API since 2023