gtkmm is the official C++ interface for the popular GUI library GTK. Highlights include typesafe callbacks, and a comprehensive set of widgets that are easily extensible via inheritance. You can create user interfaces either in code or with the Cambalache User Interface designer, using Gtk::Builder. There's extensive documentation, including API reference and a tutorial.

gtkmm is free software distributed under the GNU Lesser General Public License (LGPL).


  • Use inheritance to derive custom widgets.
  • Type-safe signal handlers, in standard C++.
  • Polymorphism.
  • Use of Standard C++ Library, including strings, containers, and iterators.
  • Full internationalisation with UTF8.
  • Complete C++ memory management
    • Object composition
    • Automatic deallocation of dynamically allocated widgets.
  • Full use of C++ namespaces.
  • No macros.
  • Cross-platform: Linux (gcc), FreeBSD (gcc), NetBSD (gcc), Solaris (gcc, Forte), Win32 (gcc, MSVC 2013 or later (gtkmm3), MSVC 2017 or later (gtkmm4)), MacOS X (gcc), others
  • Free software and free of cost for both Open Source and proprietary development.
  • Discussed, designed and implemented in public.

Other gtkmm-related libraries

gtkmm is a GUI toolkit and nothing more, and it strives to be the best C++ GUI toolkit. That mandate does not cover generic C++ data structures, an XML parser, or database access. Even our signal/slots system is part of a separate (libsigc++) library. However, gtkmm is designed to work well with all other C++ libraries.

Be sure to check out our companion libraries, glibmm (UTF8 strings, etc), pangomm (font layout), libsigc++ (signal/slots) and libxml++ (XML parser).