Extensions are configured in the /usr/lib/X11/Metro/Extensions file. Most extensions are dynamically loaded; that is, if they are needed they are loaded automatically without any additional manual configuration. An extension that is ``ON'' is loaded at server startup and never unloaded. An extension that is ``DYN'' is dynamically loaded on request by an X client XQueryExtension call. These extensions display with XListExtensions or xdpyinfo. An extension that is ``OFF'' can not be used, nor is it displayed with XListExtensions or xdpyinfo.