RDBMS introduced by IBM. Has gained quite a reputation as a database on the AS/400 platform, and on OS/390. It has recently been ported to various Unix platforms and is called the Universal Database (UDB). It supports SQL and has builtin SQL query optimization. The current version, 7.1 supports "extenders", which allow for storage and composition of XML data from within the database. Similarly, there exist extenders to handle the storage and streaming of various multimedia datatypes. IBM's DB2 is a direct competitor to the Oracle database, Sybase's adaptive server, and Informix. It supports JDBC, and has its own Call Level Interface based on ODBC. It has been ported to Sun Solaris and Hewlett-Packard HP-UX and of course IBM OS/2 and RS/6000. It also runs on systems such as Windows, Linux, NUMA-Q, and handheld device operating systems such as Windows CE and the Palm Computing platform.