FLTK VS wxWidgets

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.

The Elixir programming language is no stranger to desktop applications as the language actually supports building them out of the box. It uses wxWidgets: a C++ library that lets developers create applications for Windows, macOS, Linux and other platforms with a single code base. But wxWidgets has a very complex API, and doesn’t solve issues that usually come with desktop applications around packaging.

Qt is also 100% open/free. In fact, both are available under the LGPL, just that wxWidgets also grants an exception to not have to distribute application sources even when statically linked:

https://github.com/wxWidgets/wxWidgets#licence

But for big programs, ones written in C++? Good luck it won’t be easy at all. You might try wxwidgets or qt. I do not predict trying to click box-ify complex cli tools yielding much success.

In theory, you should be able to use FFI to interface with something like wxWindows, but you might again have problems on macOS, I don't know. And to me eyes, Wx looks a bit outdated.

This seems to be like the classic wxWidgets [1], i.e. it's an API that wraps the underlying platform's default toolkit. So on Windows it uses Windows' native controls, in Linux it seems to use GTK, and so on.

That means that the advantage is being able to write against one API, and get cross-platform compatibility, which can be nice. It also means (typically) being limited in what you can do to the least common denominator, or you (=the toolkit author) end up having to re-implement features from one platform that you want to expose but that are missing on some supported target(s). Or, of course, have an API with non-portable parts in it.

In any case, it means the "look and feel" is not the core feature of the API since that is going to be "like the target platform" and that is the point.

Given the origin, I guess Lua support is important too, here.

[1]: https://www.wxwidgets.org/

- So, I found wxWidgets. Which looked good. However, when I followed some tutorials I was getting errors. Even when I copied and pasted the tutorial code. Furthermore, the library still doesn't seem to simplify the process much.

It is the icon for WXWidgets, a programming toolkit for making user interfaces that work on Windows, Mac OS and Linux.

In general, people will use a cross-platform library to port such applications. While QT will likely never really stabilize (I'd flag it unsustainable), the https://www.wxwidgets.org/ is able to be statically linked into commercial and opensource projects at no cost without tripping GPL.

"Hiring a senior C++ developer with GTK experience is costlier"

I think you are confusing skill valuation, and operational productivity. Some have an erroneous notion talent is interchangeable. Likewise, applicants with identical base skill-sets on their CV often mistakenly believe they even have long-term employment options (outsourced, youth tax credit churn, and or senior wage suppression).

Most FOSS people are easier to train, as most already can mitigate utter chaos already. =)

There are a few like that in the C++ community. WxWidgets is the most famous/popular with this approach. But it is a library almost impossible to use in other languages because their api is heavily templated.