Gopher ( ) is a communication protocol designed for distributing, searching, and retrieving documents in Internet Protocol networks. The design of the Gopher protocol and user interface is menu-driven, and presented an alternative to the World Wide Web in its early stages, but ultimately fell into disfavor, yielding to Hypertext Transfer Protocol (HTTP). The Gopher ecosystem is often regarded as the effective predecessor of the World Wide Web.
Usage
The Gopher protocol was invented by a team led by Mark P. McCahill at the University of Minnesota. It offers some features not natively supported by the Web and imposes a much stronger hierarchy on the documents it stores. Its text menu interface is well-suited to computing environments that rely heavily on remote text-oriented computer terminals, which were still common at the time of its creation in 1991, and the simplicity of its protocol facilitated a wide variety of client implementations. Gopher's hierarchical structure provided a platform for the first large-scale electronic library connections. The Gopher protocol is still in use by enthusiasts, and although it has been almost entirely supplanted by the Web, a small population of actively maintained servers remains.
Origins The Gopher system was released in mid-1991 by Mark P. McCahill, Farhad Anklesaria, Paul Lindner, Daniel Torrey, and Bob Alberti of the University of Minnesota in the United States. Its central goals were, as stated in RFC 1436:
A file-like hierarchical arrangement that would be familiar to users. A simple syntax. A system that can be created quickly and inexpensively. Extensibility of the file system metaphor; allowing addition of searches for example. Gopher combines document hierarchies with collections of services, including WAIS, the Archie and Veronica search engines, and gateways to other information systems such as File Transfer Protocol (FTP) and Usenet. The general interest in campus-wide information systems (CWISs) in higher education at the time, and the ease of setup of Gopher servers to create an instant CWIS with links to other sites' online directories and resources, were the factors contributing to Gopher's rapid adoption. The name was coined by Anklesaria as a play on several meanings of the word "gopher". The University of Minnesota mascot is the gopher, a gofer is an assistant who "goes for" things, and a gopher burrows through the ground to reach a desired location.
Decline The World Wide Web was in its infancy in 1991, and Gopher services quickly became established. By the late 1990s, Gopher had ceased expanding. Several factors contributed to Gopher's stagnation:
In February 1993, the University of Minnesota announced that it would charge licensing fees for the use of its implementation of the Gopher server. Users became concerned that fees might also be charged for independent implementations. Gopher expansion stagnated, to the advantage of the World Wide Web which released the WWW into the public domain in April 1993, to which CERN maintained. In September 2000, the University of Minnesota re-licensed its Gopher software under the GNU General Public License. Gopher client functionality was quickly duplicated by the early Mosaic web browser, which subsumed its protocol. Gopher has a more rigid structure than the free-form HyperText Markup Language (HTML) of the Web. Every Gopher document has a defined format and type, and the typical user navigates through a single server-defined menu system to get to a particular document. This can be quite different from the way a user finds documents on the Web. Failure to follow the open systems model and bad publicity in comparison to the World Wide Web Gopher remains in active use by its enthusiasts, and there have been attempts to revive Gopher on modern platforms and mobile devices. One attempt is The Overbite Project, which hosts various browser extensions and modern clients.
Server census
As of 2012, there remained about 160 gopher servers indexed by Veronica-2, reflecting a slow growth from 2007 when there were fewer than 100. They are typically infrequently updated. On these servers, Veronica indexed approximately 2.5 million unique selectors. A handful of new servers were being set up every year by hobbyists with over 50 having been set up and added to Floodgap's list since 1999. A snapshot of Gopherspace in 2007 circulated on BitTorrent and was still available in 2010. Due to the simplicity of the Gopher protocol, setting up new servers or adding Gopher support to browsers is often done in a tongue-in-cheek manner, principally on April Fools' Day.
Technical details
The conceptualization of knowledge in "Gopher space" or a "cloud" as specific information in a particular file, and the prominence of the FTP, influenced the technology and the resulting functionality of Gopher.
Gopher characteristics Gopher is designed to function and to appear much like a mountable read-only global network file system (and software, such as gopherfs, is available that can actually mount a Gopher server as a FUSE resource). At a minimum, whatever can be done with data files on a CD-ROM, can be done on Gopher. A Gopher system consists of a series of hierarchical hyperlinkable menus. The choice of menu items and titles is controlled by the administrator of the server. Similar to a file on a Web server, a file on a Gopher server can be linked to as a menu item from any other Gopher server. Many servers take advantage of this inter-server linking to provide a directory of other servers that the user can access.
Protocol The Gopher protocol was first described in RFC 1436. Internet Assigned Numbers Authority (IANA) has assigned Transmission Control Protocol (TCP) port 70 to the Gopher protocol. The protocol is simple to negotiate, making it possible to browse without using a client.
User request First, the client establishes a TCP connection with the server on port 70, the standard gopher port. The client then sends a string followed by a carriage return followed by a line feed (a "CR + LF" sequence). This is the selector, which identifies the document to be retrieved. If the item selector were an empty line, the default directory would be selected.
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