Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.Office Open XML (also referred to as OOXML or Open XML) is a file format originally developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. Starting with Microsoft Office 2007, the Office Open XML file formats (ECMA-376) have become the default file format of Microsoft Office. In 2000, Microsoft released an initial version of an XML-based format for Microsoft Excel, which was incorporated in Office XP. In 2002, a new file format for Microsoft Word followed.[6] The Excel and Word formats known as the Microsoft Office XML formats were later incorporated into the 2003 release of Microsoft Office. Microsoft announced in November 2005 that it would standardize the new version of their XML-based formats through Ecma International, as "Ecma Office Open XML".