The ht://Dig system is a complete world wide web indexing and searching system for a domain or intranet. This system is not meant to replace the need for powerful internet-wide search systems like Lycos, Infoseek, Google and AltaVista. Instead it is meant to cover the search needs for a single company, campus, or even a particular sub section of a web site.
As opposed to some WAIS-based or web-server based search engines, ht://Dig can easily span several web servers. The type of these different web servers doesn't matter as long as they understand common protocols like HTTP.