Existing databases as of today..........

DBMS	Company	From
4th Dimension	4D S.A.S	1984
ADABAS	Software AG	1970
Adaptive Server Enterprise	Sybase	1987
Advantage Database Server	Sybase	1992
Altibase	Altibase Corp.	2000
Apache Derby	Apache	2004
Asql	Marko Tasic	2009
Datacom	CA Inc.	---
DB2	IBM	1982
DBISAM	Elevate Software	---
Datawasp	Significant Data Systems	2008
ElevateDB	Elevate Software	---
FileMaker	FileMaker	1984
Firebird	Firebird project	2000
Informix	IBM	1985
HSQLDB	HSQL Development Group	2001
H2	H2 Software	2005
Ingres	Ingres Corp.	1974
InterBase	CodeGear	1985
LucidDB	The Eigenbase Project	2007
MaxDB	SAP AG	---
Microsoft Access	Microsoft	1992
Microsoft Visual Foxpro	Microsoft	---
Microsoft SQL Server	Microsoft	1989
MonetDB	The MonetDB Developer Team	2004
MySQL	Oracle Corporation(previously Sun)	1996
HP NonStop SQL	HP	1987
Omnis Studio	TigerLogic Inc	1982
OpenBase SQL	OpenBase International	1991
Oracle	Oracle Corporation	1979
Oracle Rdb	Oracle Corporation	1984
OpenEdge	Progress Software Corporation	1984
OpenLink Virtuoso	OpenLink Software	1998
Pervasive PSQL/Bitrieve	Pervasive Software	---
Polyhedra DBMS	ENEA AB	1993
PostgreSQL	PostgreSQL Global Development Group	1989
Pyrrho DBMS	University of Paisley	2005
RBase	RBase	---
RDM Embedded	Birdstep Technology	1984
RDM Server	Birdstep Technology	1990
ScimoreDB	Scimore	2005
SmallSQL	SmallSQL	2005
SQL Anywhere	Sybase	1992
SQLite	D. Richard Hipp	2000
Superbase	Superbase	1984
Teradata	Teradata	1984
Valentina	Paradigma Software	1998 source---http://satya-dba.blogspot.in/2009/06/databases-in-world.html