Qt is a comprehensive application and UI framework for developing Linux/X11 applications that can also be deployed across many other desktop and embedded operating systems without rewriting the source code. Use the code from one single code-base and rebuild for all supported X11 versions and other platforms.
Qt includes a set of integrated development tools to speed development on X11 platforms.
Qt Creator is a complete Cross-platform IDE included in the Qt SDK. The IDE allows programmers to create, build, debug and run Qt applications accross all supported platforms.
The Qt class library includes all the functionality needed to build advanced GUI applications.
Qt is best known in the Linux community as the basis for the KDE desktop environment. Almost everything in KDE is based on Qt, and Qt forms the foundation for thousands of open source KDE applications developed by community members worldwide.
Additional Cross-Platform and Platform-Specific Development information.