doc The .doc filename extension is a native file extension used by the closed source document processing application Microsoft Office Word. Initially developed and used by Microsoft since 1983, the filename extension .doc continues to be supported natively even in the most recent iteration of the word processing application Microsoft Office Word 2013. The more recent .docx filename extension however was introduced by Microsoft in Office Word 2007, becoming the default filename extension. Documents to be saved in the .doc format are saved as Word 97, 2003 documents.
sxw StarOffice, otherwise known as Oracle Open Office, was a proprietary office suite initially released in 1985 and developed by Sun Microsystems before being acquired by Oracle. Prior to adopting the Open Document XML file format, the suite had its own proprietary components and filename extensions for word processing, spreadsheets, presentations, databases, and drawing. The .sxw filename extension was one such filename extension associated with the native file format of documents authored by the Star Office Writer (a word processor) application version 6 and above. Prior to this version, the filename extension .sdw was used.