List of relational database management systems
4th Dimension
Adabas D
Apache Cassandra
Apache Derby
Aster Data
Altibase
BlackRay
CA-Datacom
Clarion
Clustrix
CSQL
CUBRID
Daffodil database
DataEase
Database Management Library
Dataphor
dBase
Derby aka Java DB
Alpha Five
Empress Embedded Database
EXASolution
EnterpriseDB
eXtremeDB
FileMaker...