PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
4D - 4D is a relational database management system and IDE.
MySQL - The world's most popular open source database
ESM Tools - ESM Tools is a powerful and widely known software development platform that comes with a centralized model infrastructure, providing the common frame for compiling, running, downloading, and organizing models (ones or multiple).
SQLite - SQLite Home Page
ApexSQL - ApexSQL is a complete suite of tools intended for SQL servers for DBAs and developers that streamlines and automates SQL Server database management and development processes.