SQL
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Ted Codd in the early 1970s. This version, initially called "SEQUEL" ("Structured English Query Language"), was designed to manipulate and retrieve data stored in IBM's original quasi-relational database management system, System R, which a group at IBM San Jose Research Laboratory had developed during the 1970s.
MaxDB
The database development started in 1977 as a research project at the Technical University of Berlin headed by Rudolf Munz. In the early 1980s it became a database product that subsequently was owned by Nixdorf Computer, Siemens-Nixdorf, Software AG and today by SAP AG. It has at various times been named VDN, RDS, Reflex, Supra 2, DDB/4, Entire SQL-DB-Server and Adabas D. In 1997 SAP acquired the software from Software AG and developed it as SAP DB, releasing the source code under the GNU General Public License in October 2000.