The CERN httpd (also known as W3C httpd) is a generic public domain full-featured hypertext server which can be used as a regular HTTP server. The server is typically running on port 80 to serve hypertext and other documents but it can also serve as a proxy -- a server on a firewall machine -- that provides access for people inside a firewall to the outside world. When running as proxy httpd may be configured to do caching of documents resulting in faster response times.