MariaDB, MySQL, MSSQL, PostgreSQL and SQLite made easy.

HeidiSQL is free software, and has the aim to be easy to learn. "Heidi" lets you see and edit data and structures from computers running one of the database systems MariaDB, MySQL, Microsoft SQL, PostgreSQL and SQLite. Invented in 2002 by Ansgar, HeidiSQL belongs to the most popular tools for MariaDB and MySQL worldwide.

• HeidiSQL @ GitHub.

A High Performance Open Source MySQL Proxy.

ProxySQL is an open source high performance, high availability, database protocol aware proxy for MySQL

• ProxySQL @ GitHub.
• Early MySQL engineer questions whether Oracle is unintentionally killing off the open source database @ The Register

PostgreSQL foreign data wrapper for MySQL.

This PostgreSQL extension implements a Foreign Data Wrapper (FDW) for MySQL.

You no longer have to search for cryptic or incomprehensible information from MySQL query plans. All EXPLAIN outputs are transformed into data that is easier to grasp.

The world's most advanced open-source database cluster.
Galera Cluster for MySQL is a true Multi-Master Cluster based on synchronous replication. It’s an easy-to-use, high-availability solution, which provides high system up-time, no data loss and scalability for future growth.

Database management in a single PHP file.

Adminer (formerly phpMinAdmin) is a full-featured database management tool written in PHP. Conversely to phpMyAdmin, it consist of a single file ready to deploy to the target server. Adminer is available for MySQL, MariaDB, PostgreSQL, SQLite, MS SQL, Oracle, Elasticsearch, MongoDB and others via plugin.

• Adminer @ GitHub.

MyDumper is a Logical Backup Tool. It has 2 tools:

• mydumper which is responsible to export a consistent backup
• myloader reads the backup from mydumper, connects the to destination database and imports the backup.

Both tools use multithreading capabilities