The ITP/MDK Repository supports most major commercial database systems such as Oracle, Microsoft SQL Server, and IBM DB2/400. It is perhaps less well-known that it also supports several major Open Source database systems, including MySQL and PostgreSQL. Support for Sun Microsystems' MySQL database system has been included for quite some time. Support for the independent PostgreSQL database system was recently released in "beta" and will be fully supported in an upcoming release.

Both MySQL and PostgreSQL are feature-rich enterprise class database systems which are used in production sites around the world.
MySQL has gained high popularity in the Linux/UNIX world over the years due to its simplicity but has gained enterprise-level features over the years. PostgreSQL is renowned for its standards compliance and its enterprise-level stability and scalability. Enterprise support is available for MySQL from Sun Microsystems, and for PostgreSQL from a large number of commercial companies around the world.