IMO, Tk is by far the best for targeting multiplatform desktop. Qt is a close second and Gtk is "sticks out like a sore thumb, but works"

I don't think Tk runs on iOS, which is why Tk is usually disqualified in "multiplatform" recommendations

MAUI and Xamarin.Forms both have "okay" linux support last time I checked.

To put the question a bit more nicely than my sibling, don't Tk apps all look... really bad? I don't know if I've ever seen a Tk app that tried to mimic native widgets at all.

For example, the most prominent Tk application I'm aware of looks like this on Windows: https://upload.wikimedia.org/wikipedia/commons/2/2b/Scid_4.6... On Linux (where I use it), it looks even worse.

While Qt doesn't use real native widgets on all platforms (IIRC), it at least seems to effectively mimic them under most conditions.

Last time I checked (years ago), apps using ttk widgets (rather than old tk widgets) look nearly native on Windows, but still ugly on Linux (matching neither GTK nor Qt themes).

ttk (which was introduced in tcl 8.4, circa 2002) uses native widgets on Windows and Mac. The default theme on linux is ugly, but there are reasonable themes available.

There was an attempt at a GTK backend for ttk on linux, but apparently there were technical difficulties so it was abandoned.

Tk also looks like ass in today's environment of ｍｏｄｅｒｎ apps with their abundance of white space and dearth of affordance. Your Windows 9x-like Tk app will stick out like a sore thumb.

FWIW, I'm in the same bucket and I'm leaning toward Blazor. There's a big push in .NET 6 to deliver "Blazor Desktop", which is essentially more native wrappers around Blazor Server: https://github.com/dotnet/aspnetcore/issues/27217

Might not fit your needs (it is bringing web technology to native apps, much like Electron) but I think it has more of a future than XAML. And the underlying technologies (Razor, Blazor Server) have been around for a while so you can get started now even if all the pieces aren't quite there.

edit: rereading the MAUI repo, it looks like hosting Blazor inside a MAUI app will be an option. Nice.

Unless something has changed recently, MAUI won't support Linux on release.

Have you looked Flutter? It is mobile-first, but does native desktop applications as well. Very battle tested and natively compiled fast code.

> Very battle tested

Desktop support is very new and still in beta: https://flutter.dev/desktop

I prefer C#/F# over Dart, but Flutter is promising, and I continue to check in once and a while. I usually overcome PL preferences when the platform or toolkit is compelling. I remember Notch (of Minecraft fame) adopted Dart very early on, and I actually tried it out back then. Somebody had written a Lisp in Dart. I really like F#, and it seems to be sidelined all the time with .NET. There are more and more ways to write C# in a functional way, and it has become the lingua franca of many game engine/3D media creation tools like Unity, Wave Engine, Flax, and Stride to name a few.

Very early days still but support for C# is on the roadmap https://hydro-sdk.io/

I don't see the hate around Flutter here on HN. Yes, it's Google, it's bound(?) to die. But for now, people are productive with it.

> battle tested

Desktop support is far from the ideal situation(alpha). As far as I'm aware, the iOS jank is still an issue.

Flutter looks great on paper, but is a pain to use in real projects unless your app 90% overlaps with one of the included samples.

Also, it's Google. You never know if it will be around next year which means using it in production is a huge risk.

Java and C# are "battle tested." Flutter is an experimental Google project.

I'm not sure what your bar is for "experimental", but Flutter is one of the most popular UI toolkits out there, with many 100m+ MAU apps using it, including tens from Google itself. It's already shipped a 2.0 release, has 15,000+ packages on the pub.dev package server, is the framework Ubuntu has settled on for new desktop apps, has hundreds of active contributors, and is one of the top ten OSS projects on GitHub.

"Experimental" feels like an odd word choice, if you're truly trying to offer useful information.

[Disclosure: I work on the Flutter team.]

A lot of devs are risk adverse when choosing platforms for projects. There's still risk as in, will this still be supported in 3-5 years and is the API going to change so much in 1-2 years I'll be rewriting significant portions of my application.

I've been passively looking at Flutter with interrest.

Also, the Dart lang team seems to consider Flutter a first class citizen and has been modifing the language for it specifically. From syntactical sugar for Flutter's constructors to carefully selecting language features considering muilti-target platform performance.

It really is the project to beat. I am not sure how you are gonna drop a framework over C# and compete with a framework/lang combo long term.

Some people think like this: if i write an app and come back in 10 years, is it still going to work, compile, and be possible to update? By that benchmark very few platforms are acceptable, and they are mostly first party.

That standard makes sence if you have a rigid hardware-like approach

Yeah, that makes a lot of sense for certain platforms. I've spent a lot of my career working with enterprise customers, some of whom are comfortably running 20 year old software written with something like WPF. And in general, that would be true of Flutter too -- on a platform like Windows, it will work at least as long as the underlying Win32 APIs are available.

(Of course, that's not a viable test for most mobile frameworks. I suspect that an iOS Xcode project from 2011 would not run without rework, nor an app written for Android Honeycomb.)

Flutter is open source, which provides some automatic measure of protection against obsolescence. And companies like Toyota who are building it into embedded systems like cars that will still be around in 20+ years.

Doesn't use native controls

It will be out with dotnet 6 later this year.

I think I may have gotten this tech mixed up with Avalonia. Though, one integrates the other IIRC?

Try QtQuick2 if you want to target mobile, too. QtWidgwts for desktop only.

Does Godot the game engine count? I've seen it used in a pixelorama and some map modeling program. Also it's cross platform with c# support and gdscript pretty easy to understand.