The Zotero word processor plugins for Word for Mac 2008 and 2011 don't rely on a toolbar, but add a “Zotero” entry to the AppleScript menu (the manuscript icon to the right of the Help menu). Note that most menu commands are also available through shortcut keys.

The reason for using the AppleScript menu is that Word for Mac 2008 lacked support for Visual Basic for Applications (VBA), which made it impossible to create a toolbar (VBA support has subsequently been restored in Word for Mac 2011).