Libsigc++ is part of the greater GNOME code base.

• gtkmm widget wrapper
• GTK+ widget set
• Gnome project

There are a number of other C++ callback systems and publications on construction of callback systems.

• Boost Signals
• Trolltech signal system (part of Qt widget set)
• (Send us a link you find worth mentioning here.)

Here is a list of some of the projects that use libsigc++. (Have a project which is using libsigc++? Mail us.)

• glibmm and gtkmm
• Libpropc++: Creating and effective using properties in C++
• Yehia: Extension library with support for cross-threaded signal emission.
• GFC: Alternative C++ wrapper for the GTK+ widget set.
• Libuta
• The WorldForge Project