DBeaver - DBeaver - Universal Database Manager and SQL Client.
MySQL - The world's most popular open source database
MySQL Workbench - MySQL Workbench is a unified visual tool for database architects, developers, and DBAs.
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.
SQLite - SQLite Home Page