• Ensure only one open session per user
• Extends the standard Django database session backend
• Automatically logout previously existing sessions
• Optionally enforce a timeout before allowing a new login
• Works with Django 1.4+

1. Add unique_session in INSTALLED_APPS.
2. Use SESSION_ENGINE = "unique_session.backends.session_backend"
3. (Optional) Add "UNIQUE_SESSION_BLOCK_TIME = <seconds>" to enable the timeout.
4. (Optional) Add "UNIQUE_SESSION_WHITELIST = (<uid1>, <uid2>,...)" to whitelist some users (from their numeric id) so that they'll be exempt to the blocking mechanism.
5. Run syncdb.

GPLv3