Detailed Info. On DOCX File Extension
Primary association: Word
Company: Microsoft Corporation
Mime type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Identifying characters Hex: 50 4B 03 04 , ASCII: PK
DOCX file extension is primarily associated with Word application of Microsoft® Office version 2007-2010. Word 2007 is document authoring platform but is suffixed with four letter extension unlike earlier versions which supports three letter extension suffix (DOC).
Additionally; DOCX supports Open XML format document specification which aside contributing to reduce file size makes developers life much easier building applications over Word itself. All the same open XML specification promises availability of Office 2000, XP and 2003 components to perform necessary document conversions.
However; Office versions from 2007 onwards supports both DOC as well as DOCX file extension to author documents in. With OpenXML Document viewer which also has Firefox extension convert these files to view them on browser online.
Useful Resources: OpenXML Document Viewer, Microsoft Office Open XML Formats Guide, Open Document Fellowship
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