Qt is programmed in C++, where the programming language is extended by the pre-processor MOC (meta-object compiler) with features such as the elementary signal and slot mechanism (enables event-controlled communication between program objects). To do this, the pre-processor generates C++ conforming to the standard from the Qt source code, even before compiling, which means Qt applications with current C++ compilers such as GCC, ICC, MinGW or MSVC can be translated. Newer versions of the framework also offer access to the Qt’s own markup language QML, which ensures simplifications, particularly with GUI development. Aside from these internal language solutions, there are various connectivities supplied by third party providers for other program languages such as Python, Ruby, Go, Java and PHP.
With qmake (standard solution) and Qbs (QtBuild Suite) the framework holds two of its own build-systems, where other systems such as CMake can also be used. Users also have their own integrated development environment, Qt Creator, which has a code editor among other things, and enables quick access to selected components.