gtkmm-utils is a collection of high level utility functions, classes and widgets written on top of gtkmm and glibmm C++ libraries. It includes:
I announced the project on August 26, 2007.
The last version of gktmm-utils was 0.4.1, released on December 2, 2008. gtkmm-utils is licensed under the LGPL v2.1 and available on GitHub.
gtkmm-utils is among my past work.