I want to learn desktop application development for Linux and compare it with my professional experience maintaining Windows Forms applications in VB and C#. I also have experience with Java, Python, and C++, and I'm especially interested in using C++ to deepen my skills.
The main options I've been considering are Qt and GTK. I currently use Arch and Fedora with KDE, although I'm not sure how much the desktop environment should influence the choice. Ideally, I'd like to build applications that look and work well across different Linux desktop environments, and possibly support Windows and macOS too. Which toolkit and language would be the best fit, and should I consider alternatives such as Avalonia?
4 Answers
Qt is probably the strongest fit for your goals. It is designed primarily around C++, has mature support for Windows, Linux, and macOS, and works well across different desktop environments. Since you use KDE, Qt will also feel especially natural there, though Qt applications can run on other environments too. Qt Widgets are the traditional option, while Qt Quick with QML provides a more modern UI approach and is worth learning if you want a flexible, polished interface.
Qt is a full framework rather than just a UI library, so you can use only the parts you need. Its own classes, such as QString and various containers, integrate well with the C++ standard library, so you don’t have to choose exclusively between Qt and STL types. For a conventional desktop application, Qt Widgets are straightforward; for newer interfaces, Qt Quick is worth the additional learning curve.
Since you already develop Windows Forms applications in C#, Avalonia is worth investigating. It offers a familiar XAML-style approach and targets Windows, Linux, and macOS. If your main goal is to transfer your existing C# and desktop UI experience, it may be quicker to become productive with than moving to C++ and a new toolkit. If learning C++ is part of the goal, though, Qt remains the more natural choice.
GTK is primarily a C toolkit, even though bindings exist for languages such as C++ and Python. It can work across desktop environments, but cross-platform applications may require more effort to look consistent. Be cautious with GTK 4 and libadwaita if supporting non-GNOME desktops is important, since their styling and title-bar choices may not blend well elsewhere. A carefully designed Qt application often looks more consistent on GTK-based desktops than a GTK application does on other environments.
Qt Quick is especially useful when you want the interface to be separated from the application logic. The QML syntax takes some getting used to, but it can make modern layouts and animations much easier to build.