A brief overview of Qt in preparation for learning Qt programming in a Qt programming tutorial series. Learn to write cross platform GUI applications using Qt Creator and the C++ programming language.
Part 1 of the Qt Creator C++ Tutorial
Go to the Qt Programming Tutorial Series Table of Contents
What is Qt?
Qt is a toolkit for creating GUI (Graphical User Interface) applications on multiple platforms. The following quotes from the Qt Wiki describes Qt:
Qt is a cross-platform application development framework for desktop, embedded and mobile.
Qt is not a programming language on its own. It is a framework written in C++.
Quotes from: About Qt page of the Qt Wiki
Qt is supposed to be pronounced “cute”.
References:
Qt Programming Tutorial with Qt Creator and C++
This Qt programming tutorial series teaches how to write GUI (Graphical User Interface) applications in C++ using Qt Creator.
Qt Creator is an IDE used to graphically design Qt GUI windows, as well as to edit C++ code. The following image shows Qt Creator being used to lay out a simple window for a GUI application.

After building a project in Qt Creator, an executable application is produced. The image below shows a simple application built using Qt creator.

More About Qt
Qt Programming Languages
Although we use C++ in this Qt tutorial series, Qt applications can be programmed using several other languages. This is made possible through language bindings. Language bindings are a wrapper that allow other languages to use Qt, although Qt is written in C++. Some of the languages supported through bindings are C#, Python, Ring, Go, Rust, PHP, and Java. See the Wikipedia list of language bindings for Qt 5.
Supported Platforms
Qt can be used to create GUI as well as cross-platform applications that run on platforms such as Linux, Windows, macOS, Android and embedded systems. See the Qt Wiki list of supported platforms for more information.
Qt License
Qt is available under various licenses. The Qt Company sells commercial licenses, but Qt is also available as free software under several versions of the GPL and the LGPL. See the license FAQ for more information.
Qt Versions
The current major release of Qt is version 5.x which is used in this tutorial series. Don’t confuse this with the version of Qt creator which currently has a major version number of 4.x.