Popppy
Population Propogation in Python. Simulate births, marriages, deaths
...Beyond that the input parameters fertility rate, marriage age and mortality rates could change in an unpredictable manner. The tool could also be useful and fun for a student, for anyone curious about near-future demographics or CO2 emissions, or curious amateurs. Since it's Open Source (<2000 lines of Python code) you can make your own changes.
It runs from the command line and should run on any (MS WIndows, Linux/Unix/Mac OSX) platform running Python 3. A non-Python MS Windows pre-compiled Popppy executable/binary is included for those who just want to run it without having the bother of installing Python 3.x or not wanting to change the source code.