Open PostgreSQL Monitoring - Oversee and Manage Your PostgreSQL Servers
Errbit - The open source error catcher that's Airbrake API compliant
SQLAlchemy - SQLAlchemy is the Python SQL toolkit and Object Relational Mapper that gives application developers the full power and flexibility of SQL.
Redsmin - All-in-One GUI for Redis. Thightly crafted developer oriented, online real-time monitoring and administration service for Redis.
SqlPad - Run SQL in your browser and chart the results
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.