wxWidgets Is a mature GUI toolkit that uses each platform's native API, so provides a native look and feel from one codebase. This makes it more thoroughly cross-platform than
FOX is a C++ based Toolkit for developing Graphical User Interfaces easily and effectively. It offers a wide, and growing, collection of Controls, and provides state of the art f...
IUP is a multi-platform toolkit for building graphical user interfaces. It offers a simple API in three basic languages: C, Lua and LED. IUP's purpose is to allow a program s...
The Clutter Project is based on OpenGL or OpenGL ES which means it can run on anything that supports OpenGL ES. Qt LGPL and other GUI cross platform tool kits are generally limi...
NanoGUI is a a minimalistic cross-platform widget library for OpenGL 3.x. It supports automatic layout generation, stateful C++11 lambdas callbacks, a variety of useful widget ty...
Tk is a graphical user interface toolkit that takes developing desktop applications to a higher level than conventional approaches. Tk is the standard GUI not only for Tcl, but f...