apt-cacher.pl is a CGI which will keep a cache on disk
apt-cacher.pl is a CGI which will keep a cache on disk of Ubuntu Packages and Release files (including .deb files) which have been received from Ubunntu distribution servers on the Internet. When an apt-get client issues a request for a file to apt-cacher.pl, if the file is already on disk it is served to the client immediately, otherwise it is fetched from the Internet, saved on disk, and then served to the client. This means that several Debian machines can be upgraded but each package need be downloaded only once. When running multiple machine with the same distribution
