Very different. Tauri directly embeds/links to the web view runtime, and calls the APIs directly to setup the window. WebUI finds a browser installed or already running, and launches it to a localhost server hosting custom content.

>Is this basically Tauri, but with zig instead of Rust?

WebUI is language agnostic so I guess Tauri but not limited to Rust would be a better description.

Kind of but also not. Tauri uses the default on the platform it runs on, this zig-webui project seems to be able to use every major browser and every major platform. For example, Firefox, Chrome and Edge all seem to be available for Windows, Linux and macOS in zig-webui, while Tauri would use a specific engine for a specific platform (by default at least).

Tauri can use a separate browser runtime if required. The use default is a space saving mechanism.

They are working on servo implementation, but it's long time to go.

Tauri has problem on Linux, webkit2gtk has lower performance etc. I know I have problems with three.js, others with svg

Additionaly communication speed between backend and frontend is bottleneck (serialisation to string) and you must use custom protocols to effectively communicate/send large data, zero copy binary protocol isn't possible at the moment

I've been looking into Tauri and I'm curious if you could expand on the known problems with three.js and svg? Thanks.

Is this described somewhere? I couldn't find anything in the configuration (https://tauri.app/v1/api/config & https://beta.tauri.app/references/v2/config/) about it, maybe I scanned through it too quickly?

Unless you're referring to using tao and wry as libraries in your own application, but I guess that would be kind of cheating as it's not really a part of Tauri per-se in that case.