So, since this is the top post on Hacker News, and the website's description is a bit too high level for me, what does Servo let me do? By "web technologies", does it mean "put a web browser inside your desktop app"?
Electron = Node.js + CEF
Tauri = Rust + webview
Tauri has an experimental branch to use Servo to provide a bundled webview. Currently it relies on a system-level webview, like Edge on Windows, Safari on MacOS, and webkit-gtk on Linux.