PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
DBeaver - DBeaver - Universal Database Manager and SQL Client.
MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
DataGrip - Tool for SQL and databases
Amazon Aurora - MySQL and PostgreSQL-compatible relational database built for the cloud. Performance and availability of commercial-grade databases at 1/10th the cost.
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.