The latest version of the Word for Windows plugin for Zotero 3.0+ is 3.1.15 (compatible with Word 2003-2013 excluding Word 2010 Starter Edition, and Firefox 24-28).
More info can be found on the Zotero's page
The latest version of the Mac Word plugin for Zotero 3.0+ is 3.5.7 (compatible with Word 2004-2011 and Firefox 4 or later).
More info can be found on the Zotero's page
Word Plugins for StandAlone
Zotero Standalone Users: Word processor plugins are included with Zotero Standalone, and can be installed from the Zotero preferences from the Cite Pane.
