caching proxy server for software repositories

 Apt-Cacher NG is a caching proxy for downloading packages from Debian-style
 software repositories (or possibly from other types).
 .
 The main principle is that a central machine hosts the proxy for a local
 network, and clients configure their APT setup to download through it.
 Apt-Cacher NG keeps a copy of all useful data that passes through it, and when
 a similar request is made, the cached copy of the data is delivered without
 being re-downloaded.
 .
 Apt-Cacher NG has been designed from scratch as a replacement for
 apt-cacher, but with a focus on maximizing throughput with low system
 resource requirements. It can also be used as replacement for apt-proxy and
 approx with no need to modify clients' sources.list files.