pmcyg is a tool for creating customized collections of Cygwin packages together with the Cygwin installer. This enables self-contained distributions to be created without having to mirror the entire set of Cygwin packages. For example, it can create a single CD-ROM or DVD from which a personalized version of Cygwin can be installed on machines not connected to the Web. A basic installer can be created in less than 25MB; a full set of Cygwin packages might fill a DVD-ROM; or a selection of packages can be constructed to suit your chosen installation medium. pmcyg will then download these and all their dependencies automatically. pmcyg can be used either as a command-line script or via a simple graphical interface.