FLTK VS Slint

Another dark horse is FLTK: https://www.fltk.org/. For utilities this might be your best choice, especially because static linking is supported. This is mostly a C++ solution but there are bindings to other solutions.

Fl_Flex (shameless plug!) is now officially in upstream FLTK since 1.4 for a "flexbox style" layout manager.

Go ahead and sell an FLTK product then. I'm sure you go to https://www.fltk.org/ and think those GUI's look awesome you delusional moron

FLTK

A few examples: Dear ImGui, SFML, FLTK. Probably even Tk could be used.

FLTK (Fast Light Toolkit) is a lightweight, cross-platform supported toolkit for building GUIs. FLTK is supported on Windows, macOS, and UNIX systems and was originally built for C++. If you use the FLTK toolkit to create a GUI application, the application looks the same on all supported operating systems.

There are a lot of options and they're not that hard to find... Qt, wxWidgets, FLTK, IUP come immediately to mind.

FLTK. It's a cross-platform C++ GUI toolkit for UNIX®/Linux® (X11), Microsoft® Windows®, and MacOS® X.

As an anecdote, the three top contributors to sixtyfps are ex-Qt people. I think it is not anecdotal that there is at least some degree of overlap and competition between Rust and C++, and that this is a market that surely The Qt Company is watching.

SixtyFPS (https://sixtyfps.io/) is in progress for Rust, but it is still early days. It also does not technically use a native toolkit (it uses Qt), but I believe that might be on roadmap. For traditional GUI apps, I think the lack of a table or tree widget is the most limiting for the time being. They have stated they intend to remedy that.

The most promising GUI hasn't been posted here, SixtyFPS. It's in it's early stages and not FOSS, but it's built by some ex-QT cats and has a lot of potential.

People have been recommending https://sixtyfps.io/ to me.

There is already a project to make a Qt like GUI toolkit in Rust: https://sixtyfps.io/ It is really similar to Qt https://sixtyfps.io/releases/0.1.5/docs/rust/sixtyfps/index.html

People are doing that too. https://sixtyfps.io/ is basically a Qt clone in Rust, actually developed by previous Qt developers.

spdlog, a pretty useful and more and more commonly used logging library for C++.\ SixtyFPS, an emerging GUI library for Rust, but you can use it in multiple languages. It uses OpenGL or Qt currently as backend (well, it's a new library and they wanted two from the get-go to make sure their abstractions are done right/well enough). They started a company this year for it too.

Just so some are not aware, there's a new project called sixtyfps by some people who were in the Qt world for long. I didn't take a deep dive into it but it looks promising.