Impressive work.

I wonder if you've looked into what it would take to implement accessibility while maintaining your no-Rust-dependencies rule. On Windows and macOS, it's straightforward enough to implement UI Automation and the Cocoa NSAccessibility protocols respectively. On Unix/X11, as I see it, your options are:

1. Implement AT-SPI with a new from-scratch D-Bus implementation.

2. Implement AT-SPI with one of the D-Bus C libraries (GLib, libdbus, or sdbus).

3. Use GTK, or maybe Qt.