Open docx Files in Firefox without Office 2007
If you like to open .docx files without Office Word 2007, there’s a new Firefox extension from Microsoft that should help. Available for Windows as well as Linux machines.
Open DOCX files as an HTML document in any web browser
Called OpenXML viewer, this plug-in (download link) lets you read docx files inside the Firefox browser just like any other HTML web page while retaining all the text formatting and layout.
There’s a command-line version of OpenXML viewer (download link) available as well for converting docx documents into HTML files that you may then open in any other web browser.