Procedures that begin with ``XFExternalInitProc'' are evaluated when XF is started. This allows it to run initialization code that should be executed only when XF is running. XF allows the specification of a startup file via the commandline option -xfstartup. The default name for this file is ``.xf_init''. This file is evaluated when XF is started. Here additional code can be merged adding new functionality to XF .