BREAKTRU AUTOSIM 

A simulation of a NYC Transit Authority train traveling by automatic signals with working stop arms. Working circuit drawings show how the signal system relays function while the train passes over track circuits.
signals trains subway circuits nx transit railroad demo home family fun

libpropc++ (for C++) 

Template library for properties in C++ (used like 'widget.color = "red";). In class Widget use: prop::PropertyWidget, Color, &Widget::set_color, &Widget::get_color color; Binding properties to auto-synchronize their values.
c++ properties c++ template library c++ library foundational library libsigc++ signal programming oo programming object oriented programming object orientated programming signals gui programming object oriented methodology oo method oo methodology