Python observer pattern (callback/event system). Modeled after Qt Signals & Slots (but independent of Qt)

Lightweight C++ Signals and Slots implementation

lua oop serilize datastructure

Another Signal/Slot with a focus on automatic connection handling

a simple management based on signals and slots

C++ signal/slot implementation based on wl_signal/listener

yet another signal header

basic animation loop demo example in C++ Qt

Qt Named Slot Example

A very basic Julia implementation of signal-slot pattern