PostgreSQL, often simply Postgres, is an object-relational database management system(ORDBMS) available for many platforms including LinuxFreeBSDSolarisMicrosoft Windows and Mac OS X. It is released under the PostgreSQL License, which is an MIT-style license, and is thus free and open source software. PostgreSQL is developed by the PostgreSQL Global Development Group, consisting of a handful of volunteers employed and supervised by companies such as Red Hat and EnterpriseDB.