MySQL - The world's most popular open source database
Sesame Database Manager - Lantica Software, LLC - Sesame, A Q&A-compatible Database Manager.
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
XtraBuild Designer - XtraBuild offers software development tools for database and reporting applications. No coding!
SQLite - SQLite Home Page
Sheep - Membership and events for SMEs and nonprofits