An XML-based file format for office applications standardized by OASIS in 2005 and ISO in 2006. Officially the "OpenDocument Format for Office Applications," OpenDocument is supported in OpenOffice 2.0, StarOffice 8 and other word processors and text-based applications.
An Open Standard
OpenDocument was designed to be used without licensing restrictions and is an alternative to Microsoft's proprietary Office formats as well as Open XML.
A Lot of "Open" Products
The Apache OpenOffice suite supports the OpenDocument format; however, OpenDoc and Office Open XML are not related to OpenDocument. See Apache OpenOffice
and Office Open XML