gtkmm-documentation is an open source package that contains a gtkmm manual for GTK/GNOME developers. gtkmm is a C++ API for GTK+.
gtkmm is an open source software that features inheritance to derive custom widgets, type-safe signal handlers, in standard C++, polymorphism, use of standard C++ library, including containers, iterators, and strings, full internationalization with UTF-8, complete C++ memory management, object composition, and automatic deallocation of dynamically allocated widgets.
Moreover, gtkmm features full use of C++ namespaces, no macros, and it is cross-platform, supporting Linux (gcc), FreeBSD (gcc), NetBSD (gcc), Solaris (gcc, Forte), Windows (gcc, MSVC++ .Net 2003), Mac OS X (gcc), and other OSes