DOCX is an advanced version of the DOC file format and is much more usable and accessible than the latter at any given time. Unlike the DOC file, the DOCX file is not an extensive file format. Instead, it appears as being a single file while actually maintaining an archive of small package file of less than 10kb. This makes this new version more convenient to archive since they can also be unzipped with software other than the Office Suite and it's easy to send DOCX document files as attachments with emails. The DOCX file extension manifests the Microsoft Office Open XML international standard for all kinds of Office documents. It is effectively brought in use by the Microsoft applications for Windows (Word 2007, 2010, and 2013) and Mac OS X (Word 2008 and 2011), as well as a large number of other applications such as OpenOffice Writer which is an open source program for word processing.