| MySQL | Michael Widenius, David Axmark, Allan Larsson | Open-source RDBMS known for its speed, reliability, and ease of use |
| PostgreSQL | Michael Stonebraker | Open-source RDBMS known for its powerful features and standards compliance |
| Microsoft SQL Server | Microsoft Corporation | Commercial RDBMS known for its integration with other Microsoft products and ease of use |
| Oracle Database | Lawrence Ellison, Bob Miner, Ed Oates | Commercial RDBMS known for its scalability and reliability |
| IBM Db2 | IBM Corporation | Commercial RDBMS known for its performance and integration with IBM products |
| MariaDB | Michael Widenius | Open-source RDBMS based on MySQL with additional features and improvements |
| SQLite | D. Richard Hipp | Open-source RDBMS known for its small size, speed, and portability |
| SAP HANA | SAP SE | Commercial in-memory RDBMS known for its performance and real-time data processing |
| Teradata | Teradata Corporation | Commercial RDBMS known for its scalability and data warehousing capabilities |
| Informix | IBM Corporation | Commercial RDBMS known for its performance and ease of use |
| Sybase ASE | Sybase Inc. | Commercial RDBMS known for its performance and reliability |
| Amazon Aurora | Amazon Web Services | Cloud-based RDBMS known for its scalability and performance |
| Couchbase | Couchbase Inc. | Open-source NoSQL database with support for SQL-like queries and ACID transactions |
| Redis | Salvatore Sanfilippo | Open-source in-memory data structure store used as a database, cache, and message broker |
| Apache Cassandra | Facebook, Inc., Apache Software Foundation | Open-source distributed NoSQL database known for its scalability and fault tolerance |
| Apache HBase | Apache Software Foundation | Open-source distributed NoSQL database modeled after Google's Bigtable |
| Apache Hive | Apache Software Foundation | Open-source data warehouse infrastructure built on top of Hadoop |
| Apache Phoenix | Apache Software Foundation | Open-source RDBMS built on top of Apache HBase |
| Apache Spark SQL | Apache Software Foundation | Open-source distributed RDBMS built on top of Apache Spark |
| ArangoDB | Claudius Weinberger, Frank Celler, Jan Steemann | Open-source multi-model database with support for graph, document, and key-value data |
| Citus | Citus Data | Open-source distributed RDBMS built on top of PostgreSQL |
| CockroachDB | Cockroach Labs | Open-source distributed SQL database with support for ACID transactions and strong consistency |
| FaunaDB | Fauna, Inc. | Cloud-native serverless NoSQL database with support for ACID transactions and global distribution |
| Firebird | IBPhoenix | Open-source RDBMS known for its small size and low resource requirements |
| Greenplum | Pivotal Software, Inc. | Open-source RDBMS designed for data warehousing and analytics |
| InfluxDB | InfluxData, Inc. | Open-source time-series database optimized for storing and querying large amounts of time-stamped data |
| MemSQL | MemSQL, Inc. | Commercial in-memory RDBMS known for its scalability and real-time data processing |
| MongoDB | MongoDB, Inc. | Open-source NoSQL document-oriented database with support for JSON-like documents |
| Neo4j | Neo4j, Inc. | Commercial graph database optimized for storing and querying graph data |
| OmniSci | OmniSci, Inc. | Commercial in-memory RDBMS optimized for data analytics |