OpenSource RDBMS

RDBMS	Language	Column or Row	Cloud Native	Github Repo	Affliated Organization
Clickhouse	C++	Column	No	https://github.com/ClickHouse/ClickHouse	https://www.clickhouse.com
Greenplum DB	C/C++	Row	No	https://github.com/greenplum-db/gpdb	https://docs.vmware.com/en/VMware-Greenplum/index.html
C-Store	C++	Column	No	https://github.com/eyalroz/c-store	https://www.vertica.com/
MonetDB	C	Column	No	https://github.com/MonetDB/MonetDB	https://www.monetdbsolutions.com/
MySQL	C++/C	Row	No	https://github.com/mysql/mysql-server	https://dev.mysql.com/
MariaDB	C++/C	Row	No	https://github.com/MariaDB/server	https://mariadb.com/
PostgreSQL	C	Row	No	https://github.com/postgres/postgres	https://www.postgresql.org/, https://www.enterprisedb.com/
YugabyteDB	C/C++	Column	Yes	https://github.com/yugabyte/yugabyte-db	https://www.yugabyte.com/
FirebirdSQL	C++/C	Row	No	https://github.com/FirebirdSQL/firebird	https://firebirdsql.org/
CockroachDB	Go	Column	Yes	https://github.com/cockroachdb/cockroach	https://www.cockroachlabs.com/product/
TiDB	Go	Column	Yes	https://github.com/pingcap/tidb	https://www.pingcap.com/

OpenSource NoSQL DBMS

DBMS	Language	Cloud Native	Github Repo	Affliated Organization
ScyllaDB	C++	Yes	https://github.com/scylladb/scylladb	https://www.scylladb.com
MongoDB	C++	Yes	https://github.com/mongodb/mongo	https://www.mongodb.com
Cassandra	Java	Yes	https://github.com/apache/cassandra	https://www.datastax.com/
Redis	C	Yes	https://github.com/redis/redis	https://redis.io/
OrientDB	Java	Yes	https://github.com/orientechnologies/orientdb	https://orientdb.org/

OpenSource Vector DBMS

DBMS	Language	Cloud Native	Github Repo	Affliated Organization
qdrant	Rust	Yes	https://github.com/qdrant/qdran	https://qdrant.tech
milvus	Go & C++	Yes	https://github.com/milvus-io/milvus	https://milvus.io/
pgvector	C	No	https://github.com/pgvector/pgvector	https://www.postgresql.org/
weaviate	Go	Yes	https://github.com/weaviate/weaviate	https://weaviate.io/
FAISS	C++	Yes	https://github.com/facebookresearch/faiss	https://opensource.fb.com/
ANNOY	C++ & Python	Yes	https://github.com/spotify/annoy	https://engineering.atspotify.com/?s=annoy