Webmin is a system configuration tool for Unix-like systems. It has a web-based interface for configuring all the internals of the operating system.
The Webmin is largely based on perl, and is running as its own process, and webserver. It usually uses TCP port 10000 for communicating, and can be configured to use SSL if OpenSSL is installed. It is built around modules, which have an interface to the config files, and an interface to the webmin server. This makes it easy to add new functionality, without too much work. Webmin also allows for controlling many machines through a single interface, or seamless login on other webmin hosts in the same LAN.
http://www.webmin.com/ Webmin website