Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
DBeaver - DBeaver - Universal Database Manager and SQL Client.
Hazelcast - Clustering and highly scalable data distribution platform for Java
DataGrip - Tool for SQL and databases
Aerospike - Aerospike is a high-performing NoSQL database supporting high transaction volumes with low latency.
HeidiSQL - HeidiSQL is a powerful and easy client for MySQL, MariaDB, Microsoft SQL Server and PostgreSQL. Open source and entirely free to use.