xxmklink is a command line program to create Windows menu shortcuts and is used by most Osgeo4w install packages (as part of the base pkg-msvcrt). It's homepage is ​http://www.xxcopy.com/xxcopy38.htm

xxmklink is normally free only for personal use, however the author has granted osgeo4w special authorization:

Subject:  	Re: xxmlink.exe licence
Date: 	Fri, 07 Mar 2008 17:21:13 -0500
From: 	Yewondwossen Assefa <yassefa@dmsolutions.ca>
To: 	Kan Yabumoto - Pixelab sales <sales@pixelab.com>

 Dear Assefa:

 Thank you for contacting us for the use of XXMKLINK.
 I just looked at your OSGeo4W page on Wikipedia.
 
 Let this Email authorize OSGeo to include our XXMKLINK.EXE program
 in the OSGeo Binary Distribution and related installer packages.
 
 We charge a nominal license fee for commercial applications
 on a case-by-case basis.  In this particular case, we would like to
 give you permission to use XXMKLINK free of charge because your
 usage is for an open source project.
 
 We will be most appreciative if you give us credit for XXMKLINK
 in whatever context it fits.
 
 With regards,
 Kan Yabumoto