wxWidgets Cross-platform C++ GUI toolkit (GTK+ 3 development)

 wxWidgets (formerly known as wxWindows) is a class library for C++ providing
 GUI components and other facilities on several popular platforms (and some
 unpopular ones as well).
 .
 This package provides files needed to compile wxWidgets programs. If you
 want to compile apps using the (optional) glcanvas library you will need
 to have Mesa or OpenGL installed too.
 .
 This package also provides the wx-config script.