This project consists in a complete library management system. It handles via its command-line interface various types of customers, library items, penalties for giving back late the books, and many other points.
One builds a library by providing the number of rooms, shelves, bookcases and the miscellaneous items populating it. Then, a timer runs in background to update each day the library : it automatically applies penalties to late members, and handles the borrowing and returning of items according to their status (borrowable or not, available,...).
The main strength of this code is that thanks to the use of varied design patterns, it is easily extendable and maintainable. It is under the MIT license, so feel free to use it !