Flask, obviously. Flask-Login for the user accounts. Flask-SQLAlchemy interacting with the database. Flask-WTF and WTForms for the form handling. Flask-Mail for sending mails. itsdangerous for generating random tokens for the confirmation emails. Flask-Bcrypt for generating secret user passwords. Flask-Admin for building an administration interface. Flask-Script for managing the app. structlog for logging. Flask-DebugToolBar for adding a performance toolbar in development. gunicorn for acting as a reverse-proxy for Nginx.