Qt
A cross-platform application development framework.
Qt provides widgets, an event-driven object system (signals and slots), threading utilities, networking, multimedia, and a large standard library for cross-platform applications. C++ is the canonical language, but bindings exist for Python (PyQt and PySide), JavaScript (the QML language for declarative UIs), and several others. Qt also includes its own build system (qmake, plus the newer CMake-friendly mode) and an IDE (Qt Creator).
The toolkit dates back to 1991. Trolltech (the original Qt company) was acquired by Nokia in 2008, then sold to Digia in 2012, then spun out as the independent Qt Group in 2014. Qt is triple-licensed: LGPL-3.0 (the open-source community version), GPL-2.0 (an alternative free option), or commercial licences for proprietary application development.
KDE Plasma, every KDE application, VLC, OBS Studio, Wireshark, TeXstudio, qutebrowser, Cura, FreeCAD, Krita, and many other prominent free-software applications are built on Qt. It is the default cross-platform toolkit for many embedded GUIs as well — automotive infotainment systems, medical devices, and industrial control panels often have a Qt-based UI.
License: LGPL-3.0 / GPL-3.0 / commercial (triple)
Category: Developer tools
Website: https://www.qt.io/
Install
Debian/Ubuntu: sudo apt install qt6-base-dev Fedora/RHEL: sudo dnf install qt6-qtbase-devel Arch: sudo pacman -S qt6-base
Authors
- Qt Group and the Qt Project