Qt is a cross-platform application development framework built around C++, accompanied by Qt Creator, a visual designer, and a broad set of modules for GUI, networking, multimedia, database access, and embedded deployment. It lets teams build one codebase that compiles for Windows, macOS, Linux, Android, iOS, and embedded targets.
The official site provides documentation for each module, API references by version, release notes, examples and tutorials, and downloads for the open-source and commercial licenses. It also describes Qt Design Studio, QML and Qt Quick for fluid touch interfaces, plus tooling for translation, testing, and static analysis.
It suits desktop software vendors, industrial HMI and automotive teams, and embedded device makers that need native performance with a consistent UI layer, as well as C++ developers who want maintained bindings and long-term support releases.
Compared with web-based cross-platform stacks it produces smaller, faster native binaries, though it requires C++ or QML expertise; compared with platform-specific SDKs it trades some OS-specific polish for substantially less duplicated code.
Check the license terms carefully before shipping a product, since obligations differ between open-source and commercial editions, and pin the Qt version used across the build pipeline to avoid ABI and QML compatibility surprises.