DBeaver - DBeaver - Universal Database Manager and SQL Client.
Firebird Maestro - SQL Maestro Group vendors powerful database management and web development tools for MySQL, Oracle, SQL Server, DB2, SQL Anywhere, PostgreSQL, SQLite, Firebird and MaxDB.
RazorSQL - RazorSQL is an SQL Editor and SQL database query tool for macOS, Windows, Linux, and Mac OS X.
DbGate - Open Source Database Manager for SQL Server, MySQL, PostgreSQL, SQLite, MongoDB, Redis and more
SQL Database Studio - SQL Database Studio is professional client for Microsoft SQL Server.
SQLTools - SQLTools is a light weighted and robust tool for ORACLE database development.