Product Information

Functionality

At its core, the Qt Framework (also "Qt" on this page) provides a cross-platform API for application and device development. You can install Qt as a framework for development on a host machine, or build it from source code and install it as a runtime on embedded devices. Qt includes technical documentation and a set of essential tools to support efficient development.

This page gives an overview of Qt as a product. If you are new to Qt, see Introduction to Qt in the Qt documentation.

Functional Composition

Qt consists of modules that provide specific functionality, organized into a composite structure. The Qt Essentials modules form the foundation and are always present. Qt Add-Ons provide additional, more specialized functionality. In practice, most users install all add-ons regardless of whether they use them later.

Some add-ons are Qt Extension Modules. These modules provide isolated, specific functionality built on top of larger third-party components. As a result, they have their own release cadence, which may differ from the Qt releases.

Qt is generally available as source code and as installable prebuilt binaries for selected target and host platforms.

Licensing

Qt is dual-licensed. The Community Edition is available under Open-Source Software (OSS) licenses. Qt Group also offers Qt under a commercial license as a selection of commercial product packages, which can include commercial-only functionality.

Licensing also covers the downstream licensing of third-party components used in Qt. For more details about third-party licensing and Qt licensing in general, see the Qt Licensing page in the Qt documentation.

Qt Group defines the terms and conditions of commercial licensing on the Qt Frame Agreement page.

Qt is widely used in education. Qt for Education defines the licensing of Qt in this field.

Versions

Qt has two minor releases per year. Every fourth minor release is a long-term support (LTS) release with a longer support period, such as Qt 6.8 and Qt 6.12. Each release has a series of maintenance (patch) releases during its life cycle. Maintenance releases focus on bug and vulnerability fixes and make no changes to the core functionality. Minor releases, including LTS releases, make only minor changes to it; only a major release can change it significantly. For more details, see the Releases page in the Qt documentation.

Qt has strict, controlled governance over the evolution of its functionality, including a defined Versioning scheme and Compatibility promises. The Releases page in the Qt documentation outlines both for each release, but they can change only in a major release.

Maturity and Validity of the Scope

Qt modules have a defined life cycle.

Qt modules and functionality in Technology Preview status (see QUIP 14: Entering Technology Preview and section 2.5 of the Qt Support Terms and Conditions) are not part of the commercial Qt product offering, even though Qt provides them for preview purposes. The same applies to deprecated modules.

Qt Group generally provides conformity with global and regional regulations for the Qt Framework under a commercial license. All vulnerability fixes still apply to the dual-licensed code base and are available regardless of the licenses under which you use Qt.

Git tags on the corresponding Git branches track the release scope of a given Qt release for each Qt module and other repositories. The date of a Git tag is the release date. The release team has ultimate control over these tags.

Configurations

Qt is a cross-platform framework. You can configure and compile it for many target and host platforms.

Every supported platform has a defined set of supported configurations outlined in the Qt documentation. The Qt installation folder for a given Qt version contains files that list the configuration options used and a configuration summary for each Qt module.

Qt testing and verification use these configurations.

Other configurations, as well as builds of Qt with proprietary patches applied, are outside Qt Group's conformity commitments.

Documentation and Information Structure

The following list outlines the information sources about Qt and orders them by authority from highest to lowest.

1. Qt technical documentation
   • Qt technical documentation is part of the Qt source code.
   • The same systems host, develop, and deploy the documentation and the Qt source code.
   • Errors in the documentation count as bugs in Qt.
   • Qt Group publishes the documentation online at doc.qt.io and ships it in compiled form as offline help in Qt Creator.
   • Qt Group publishes documentation snapshots at doc-snapshots.qt.io. The information in a snapshot becomes valid only when Qt Group releases the given version.
   • Each minor release carries its own version of the documentation.
   • The documentation covers functionality according to the license of the related code.
2. Qt Group commercial product documentation
   • The commercial product documentation includes the Qt technical documentation and extends it with technical documentation about commercial-only functionality.
   • Qt Group publishes its terms and conditions, including the support terms for Qt, at qt.io/terms-conditions.
   • Qt Framework Licensing explains its licensing.
3. Qt Group company website
   • Qt Group lists Qt in its Development product range.
   • qt.io/development and other linked pages cover Qt.
   • The website content focuses on the value of Qt for users and builds on technical and commercial product information.
   • Qt Group staff members and, occasionally, partners or community members use the Qt Blog to announce and describe selected highlights and new features in Qt.
4. Qt Project sites
   • qt-project.org covers the governance of Qt as an open-source project.
   • wiki.qt.io covers the development of Qt in open source and holds relevant technical documentation.
5. Qt Forum
   • forum.qt.io hosts technical discussions for all Qt users.
   • A forum topic does not describe Qt functionality unless the Qt technical documentation covers it, even if the topic is technically correct.