A GTK+-based implementation of the wxWindows cross-platform GUI library.

wxWindows is a set of libraries that allows C++ applications to compile
and run on several different types of computer, with minimal source code
changes.  There is one library per supported GUI (such as Windows, GTK+,
Motif, and Mac).

wxWindows is free, well-established, well-documented, and very broad in
its coverage of GUI functionality.  It has some extras that make it
stand out from the crowd, such as the many convenience dialogs, built-in
HTML display and printing, virtual filesystems, easy-to-use OLE
automation controller class, Open GL support, and many other features
that make it easier to write modern and user-friendly applications.

There is also a python interface available, wxPython (see the
py-wxWindows pkg).