apt-cacher

apt-cacher is a CGI script which can be used by apt-get to request downloads of Debian packages (and release files) from the Net. Each downloaded file is cached into a directory, so subsequent requests for the same filename are filled from the cache. This is useful when you have multiple Debian installations to update, particularly if you are on the end of a slow Internet connection. apt-cacher is easy to install; you only need to have a local Web server on which you can place the CGI script and create a directory for the cache.