Right to start, going to be clear that I would not consider myself to be particularly experienced in GUI tech. I have a checklist of things that I look for whenever a "run native code in the web" project gets posted, but I haven't downloaded and checked the native performance of any of these technologies. I'm really just looking at their web demos.

That being said, on the web, Blazor is what I'm paying the most attention to right now. Being in C# might be a pro or a con for you. But Blazor will spit out an actual DOM tree, it seems to have a lot of promise from what I can see. There's a heavy emphasis on writing UI in C#, but having good interop with browser technologies and JS libraries.

On the Rust side of things, pay attention to https://www.areweguiyet.com/, they've been doing a great job of cataloging different efforts. A lot of the Rust efforts have either gone in the direction of "embed a Webrender instance in a native app" or "embed a native app in the browser." I'm not sure that's a great direction, at some point I think it might make more sense to treat the HTML as a compile target rather than an authoring language.

Again, I point towards Blazor. Not the C# part obviously, keep it in Rust. But I wish some of the Rust GUIs would take Blazor's approach and spit out separate HTML for the web (even if the results look slightly different) rather than trying to embed the same renderer everywhere.

I don't personally use Qt, but that is purely a personal preference, if you're doing native cross-platform apps, I don't think there's anything wrong with Qt. It's popular for a good reason. However, I do think that Qt's web export is really bad. It's making the same mistakes as Egui, but Egui has the benefit of clearly a large amount of work devoted to performance, UX, etc... not to say that Qt's web export hasn't had a lot of work put into it, but Equi's seems to have actually paid off, and the Qt demos don't give me that impression.

That's purely on the web though, as a user for native cross platform code I don't really have many complaints about Qt, if you like it you should keep using it.

Ionic and Quasar are obviously going to have great results on the web because they're based on React and Vue, which are web technologies -- so of course they're going to render to DOM in those situations. I'm not sure how their native performance will be. My immediate concern with both of them is that they're trying to upsell me on a license. You might also take a look at React Native if those libraries seem attractive to you. I don't know what the consensus is on whether React Native runs well on mobile devices.

And again going to stress here, I'm opinionated but I'm not an expert. I'm not really commenting on the ease of use or the architecture paradigms or language choices or anything here, I'm just looking the web demos online that these technologies have and checking to see if they run OK inside a browser.

Thanks for the reply.