OOGtk is a lightweight C++ wrapper for GTK+, EASY to use, with a simple but powerful syntax, crossplatform, header only. OOGtk is written in modern C++ and uses STL objects & templates when possible, it also avoids pointer where possible.
GGredit is library that implements base functionality for a generic graphic editor. DDraw is a diagram editor designed for Gnome that use GGredit. DDraw is inspired to DIA, it can be used to draw many different kinds of diagrams.
GtkGLExt is an OpenGL extension to GTK+. It provides additional GDK objects which support OpenGL rendering in GTK+, and GtkWidget API add-ons to make GTK+ widgets OpenGL-capable.
C++ template library for properties of objects which can be manipulated like normal member variables (widget.color = "red";). Supports binding properties with each other, so that when one property changes, other changes accordingly automatically.