The OpenDocument format (ODF, ISO/IEC 26300, full name: OASIS Open Document Format for Office Applications) is a file format for electronic office documents, such as spreadsheets, charts, presentations and word processing documents.

While the specifications were originally developed by Sun, the standard was developed by the Open Office XML technical committee of the Organization for the Advancement of Structured Information Standards (OASIS) consortium and based on the XML format originally created and implemented by the OpenOffice.org office suite (see OpenOffice.org XML). As well as an OASIS Standard it is, in its version 1.0 manifestation, a published ISO/IEC International Standard, ISO/IEC 26300:2006. The OpenDocument standard meets the common definitions of an open standard, meaning the specification is freely available and implementable.