Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design. You can find its source code and contribute to the project on GitHub.

Here is the link to Django’s official repository on GitHub: https://github.com/django/django

Remember, contributing to open-source projects like Django is a great way to improve your programming skills and help the community. Before you start contributing, make sure to read their contribution guidelines to understand the process and expectations. Also, always respect the Code of Conduct of the project.