Kirigami is KDE’s lightweight user interface framework for mobile and convergent applications. It allows Qt developers to easily create applications that run on most major mobile and desktop platforms without modification (though adapted user interfaces for different form-factors are supported and recommended for optimal user experience). It extends the touch-friendly Qt Quick Controls with larger application building blocks, following the design philosophy laid out in the Kirigami Human Interface Guidelines.
Here are the most important links:
If you're unfamiliar with CMake, the CMake Manual for Qt is a good starting point to learn more about it.
The source code for Kirigami releases is available for download from download.kde.org. GPG signatures are available alongside the source code for verification. They are signed by release manager Marco Martin.
For the first release (1.0) we prepared packages for various Linux distributions using the Open Build Service instance provided by openSUSE at software.opensuse.org/package/kirigami. These are for Arch Linux, Fedora, openSUSE Leap and TW, and Ubuntu.
By now all major distributions should ship a version of Kirigami.