Gopher is a distributed document search and retrieval network protocol designed for the Internet. Its goal are similar to that of the World Wide Web, and it has been almost completely displaced by the Web. The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. ... The application layer is the 7 th seventh level of the seven-layer OSI model. ... The domain name system (DNS) stores and associates many types of information with domain names, but most importantly, it translates domain names (computer hostnames) to IP addresses. ... Secure Sockets Layer (SSL) and its successor, Transport Layer Security (TLS), are cryptographic protocols which provide secure communications on the Internet for such things as web browsing, e-mail, Internet faxing, and other data transfers. ... Trivial File Transfer Protocol (TFTP) is a very simple file transfer protocol, with the functionality of a very basic form of FTP; it was first defined in 1980. ... FTP or file transfer protocol is a commonly used protocol for exchanging files over any network that supports the TCP/IP protocol (such as the Internet or an intranet). ... Hypertext Transfer Protocol (HTTP) is a method used to transfer or convey information on the World Wide Web. ... The Internet Message Access Protocol (commonly known as IMAP4, and previously called Internet Mail Access Protocol) is an application layer Internet protocol that allows a local client to access e-mail on a remote server. ... IRC redirects here. ... The Network News Transfer Protocol or NNTP is an Internet application protocol used primarily for reading and posting Usenet articles, as well as transferring news among news servers. ... The Network Time Protocol (NTP) is a protocol for synchronising the clocks of computer systems over packet-switched, variable-latency data networks. ... In computing, local e-mail clients use the Post Office Protocol version 3 (POP3), an application-layer Internet standard protocol, to retrieve e-mail from a remote server over a TCP/IP connection. ... Session Initiation Protocol (SIP) is a protocol developed by IETF MMUSIC Working Group and proposed standard for initiating, modifying, and terminating an interactive user session that involves multimedia elements such as video, voice, instant messaging, online games, and virtual reality. ... Simple Mail Transfer Protocol (SMTP) is the de facto standard for e-mail transmission across the Internet. ... The simple network management protocol (SNMP) forms part of the internet protocol suite as defined by the Internet Engineering Task Force. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... TELNET is a network protocol used on the Internet or local area network LAN connections. ... The BitTorrent logo BitTorrent is the name of a peer-to-peer (P2P) file distribution protocol, and is the name of a free software implementation of that protocol. ... The Real-time Transport Protocol (or RTP) defines a good standardized packet format for delivering audio and video over the Internet. ... In computing, rlogin is a Unix software utility that allows users to log in on another host via a network, communicating via TCP port 513. ... The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. ... The User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. ... The Datagram Congestion Control Protocol (DCCP) is a message-oriented transport layer protocol that is currently under development in the IETF. Applications that might make use of DCCP include those with timingconstraints on the delivery of data such that reliable in-order delivery, when combined with congestion control, is likely... The Stream Control Transmission Protocol (SCTP) is a transport layer protocol defined in 2000 by the IETF Signaling Transport (SIGTRAN) working group. ... Transport layer protocol designed originally as part of the Plan 9 from Bell Labs operating system and used to carry 9P. Its main features are: Reliable datagram service In-sequence delivery Internetworking using IP Low complexity, high performance Adaptive timeouts The original paper describing IL: [1] Categories: Computer stubs ... In computer networking, the Reliable User Datagram Protocol (RUDP) is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. ... The network layer is level three of the seven level OSI model. ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. ... Internet Protocol version 6 (IPv6) is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork. ... The Internet Control Message Protocol (ICMP) is one of the core protocols of the Internet protocol suite. ... The Internet Group Management Protocol is a communications protocol used to manage the membership of Internet Protocol multicast groups. ... In computer networking, the Address Resolution Protocol (ARP) is the method for finding a hosts hardware address when only its IP address is known. ... Reverse address resolution protocol (RARP) is a protocol used to resolve an IP address from a given hardware address (such as an Ethernet address). ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Ethernet is a large and diverse family of frame-based computer networking technologies for local area networks (LANs). ... Wi-Fi (also WiFi, wifi, etc. ... Token-Ring local area network (LAN) technology was developed and promoted by IBM in the early 1980s and standardised as IEEE 802. ... In computing, the Point-to-Point Protocol, or PPP, is commonly used to establish a direct connection between two nodes. ... The Serial Line Internet Protocol (SLIP) is a mostly obsolete encapsulation of the Internet Protocol designed to work over serial ports and modem connections. ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ... Asynchronous Transfer Mode (ATM) is a cell relay network protocol which encodes data traffic into small fixed-sized (53 byte; 48 bytes of data and 5 bytes of header information) cells instead of variable sized packets (sometimes known as frames) as in packet-switched networks (such as the Internet Protocol... Dynamic synchronous Transfer Mode , or DTM for short, is a network protocol. ... In the context of computer networking, frame relay (also found written as frame-relay) consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. ... SMDS, which stands for Switched Multi-megabit Data Services, was a connectionless service used to connect LANs, MANs and WANs to exchange data. ... Distributed computing is decentralised and parallel computing, using two or more computers communicating over a network to accomplish a common objective or task. ... A document contains information. ... In networking, a communications protocol or network protocol is the specification of a set of rules for a particular type of communication. ... WWWs historical logo designed by Robert Cailliau The World Wide Web (WWW or simply the Web) is a global, read-write information space. ...

The Gopher protocol offers some features not natively supported by the Web and imposes a much stronger hierarchy on information stored on it. Its text menu interface is well-suited to computing environments that rely heavily on remote computer terminals, common in universities at the time of its creation. Some consider it to be the superior protocol for storing and searching large repositories of information. A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system. ...

History

Origins

The original Gopher system was released in late spring of 1991 by Mark McCahill, Farhad Anklesaria, Paul Lindner, Dan Torrey, and Bob Alberti of the University of Minnesota. Its central goals are: 1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar. ... Mark McCahill (born February 7, 1956) has been involved in developing and popularizing a number of Internet technologies since the late 1980s. ... Washington Avenue Bridge at night The University of Minnesota, Twin Cities, almost always abbreviated U of M, and sometimes referred to as The U by locals, is the oldest and largest part of the University of Minnesota system. ...

• A file-like hierarchical arrangement that would be familiar to users
• A simple syntax
• A system that can be created quickly and inexpensively
• Extending the file system metaphor to include things like searches

The source of the name "Gopher" is claimed to be three-fold:

1. Users instruct it to "go for" information
2. It does so through a web of menu items analogous to gopher holes
3. The sports team of the University of Minnesota is the Golden Gophers

Gopher combines document hierarchies with collections of services, including WAIS, the Archie and Veronica search engines, and gateways to other information systems such as ftp and Usenet. A gopher is a small burrowing rodent. ... Goldy the Gopher is the team mascot The Minnesota Golden Gophers are the college sports team for the University of Minnesota Twin Cities. ... Wide Area Information Servers or WAIS is a distributed text searching system that uses the protocol standard ANSI Z39. ... Archie was the first search engine ever invented, designed to index FTP archives, allowing people to find specific files. ... Veronica is a search engine system for the Gopher protocol, developed in 1992 by Steven Foster and Fred Barrie at the University of Nevada. ... The abbreviation FTP can refer to: The File Transfer Protocol used on the Internet. ... Usenet is a distributed Internet discussion system that evolved from a general purpose UUCP network of the same name. ...

The general interest in Campus-Wide Information Systems (CWISs) ^[1] in higher education at the time, and the ease with which a Gopher server could be set up to create an instant CWIS with links to other sites' online directories and resources were the factors contributing to Gopher's rapid adoption. By 1992, the standard method of locating someone's e-mail address was to find their organization's CSO nameserver entry in Gopher, and query the nameserver ^[2]. The CSO Nameserver software was developed by Steve Dorner at the University of Illinois at Urbana-Champaign. ...

The exponential scaling of utility in social networked systems (Reed's law) seen in Gopher, and then the web, is a common feature of networked hypermedia systems with distributed authoring. In 1993–1994, Web pages commonly contained large numbers of links to Gopher-delivered resources, as the Web continued Gopher's embrace and extend tradition of providing gateways to other services. Reeds law is the assertion of David P. Reed that the utility of large networks, particularly social networks, can scale exponentially with the size of the network. ...

Decline

The World Wide Web was in its infancy in 1991, and Gopher services quickly became established. However, by the late 1990s, Gopher had almost disappeared. Insofar as information management is concerned, the progress from gopher to the web as a standard can be seen simply as a natural progression from text-based to graphical interfaces ^{[citation needed]}. Several other factors contributed to the acceleration of Gopher's decline: WWWs historical logo designed by Robert Cailliau The World Wide Web (WWW or simply the Web) is a global, read-write information space. ... 1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar. ... See also 1990s, the band The 1990s decade refers to the years from 1990 to 1999, inclusive, sometimes informally including popular culture from the very late 1980s and from 2000 and beyond. ...

• In February of 1993, the University of Minnesota announced that they would charge licensing fees for the use of their implementation of the Gopher server. ^[3] As a consequence of this some users suspected that a licensing fee would be also charged for independent implementations. ^{[4] [5]} In contrast, there was no such limitation on the World Wide Web. The University of Minnesota eventually re-licensed their Gopher software under the GNU GPL ^[6].
• Gopher's functionality was quickly duplicated by early Web browsers, such as Mosaic. Furthermore, the greater flexibility of the Web's HTML, and particularly its integration of text and graphics, encouraged the migration of content from Gopher to the World Wide Web ^{[citation needed]}.
• Gopher has an inflexible structure when compared to the free-form HTML of the Web. With Gopher, every document has a defined format and type, and the typical user must navigate through a single server-defined menu system to get to a particular document. Many people did not like the artificial distinction between menu and fixed document in the Gopher system, and found the Web's open-ended flexibility much more useful for constructing interrelated sets of documents and interactive applications.

1993 (MCMXCIII) was a common year starting on Friday of the Gregorian calendar and marked the Beginning of the International Decade to Combat Racism and Racial Discrimination (1993-2003). ... GPL redirects here. ... Mosaic is a World Wide Web browser and Gopher client developed at the National Center for Supercomputing Applications (NCSA) beginning in 1992, and officially ending on January 7, 1997. ... An example of HTML code with syntax highlighting and line numbers In computing, HyperText Markup Language (HTML) is a predominant markup language for the creation of web pages. ... An example of HTML code with syntax highlighting and line numbers In computing, HyperText Markup Language (HTML) is a predominant markup language for the creation of web pages. ...

Availability of Gopher today

As of 2006, there are still a few Gopher servers present on the net, in organizations such as the US government; a few are also being maintained by enthusiasts of the protocol, where almost all growth is occurring. 2006 is a common year starting on Sunday of the Gregorian calendar. ... ...

Some have suggested that the bandwidth-sparing simple interface of Gopher would be a good match for mobile phones and Personal digital assistants (PDAs), but so far, the market prefers Wireless Markup Language (WML)/Wireless Application Protocol (WAP), DoCoMo i-mode, XHTML Basic or other adaptations of HTML and XML. The PyGopherd server, however, provides a built-in WML front-end to Gopher sites served with it. Palm IIIxe PDA Personal digital assistants (PDAs or palmtops) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. ... Wireless Markup Language is the primary content format for devices that implement the WAP (Wireless Application Protocol) specification based on XML, such as mobile phones. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... i-mode advert on the London Underground NTT DoCoMos i-mode is a wireless Internet service popular in Japan and increasingly elsewhere. ... XHTML Basic is an XML-based structured markup language primarily used for simple (mainly handheld) user agents, typically mobile devices. ... An example of HTML code with syntax highlighting and line numbers In computing, HyperText Markup Language (HTML) is a predominant markup language for the creation of web pages. ... The Extensible Markup Language (XML) is a W3C-recommended general-purpose markup language for creating special-purpose markup languages, capable of describing many different kinds of data. ... PyGopherd is a modern Internet Gopher server written in Python and is maintained by John Goerzen. ...

Gopher characteristics

A Gopher system consists of a series of hierarchical menus. The choice of menu items and titles is set by the administrator of the server.

The top level menu of a Gopher server. Selecting the "Fun and Games" menu item...

... takes the user to the "Fun and Games" menu.

Image File history File links Download high resolution version (1400x1016, 65 KB) Summary Screenshot made by me, showing the top menu of the Floodgap. ... Image File history File links Download high resolution version (1400x1016, 65 KB) Summary Screenshot made by me, showing the top menu of the Floodgap. ... Image File history File links Download high resolution version (1400x1016, 49 KB) Summary Screenshot made by me, showing the fun and games menu of Floodgap. ... Image File history File links Download high resolution version (1400x1016, 49 KB) Summary Screenshot made by me, showing the fun and games menu of Floodgap. ...

A Gopher menu listing other accessible servers.

Gopher menu from a terminal client.

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. Image File history File links Download high resolution version (1400x1016, 62 KB) Summary Screenshot taken by me, showing a Floodgap. ... Image File history File links Download high resolution version (1400x1016, 62 KB) Summary Screenshot taken by me, showing a Floodgap. ... Image File history File links Umn_gopher_dir. ... Image File history File links Umn_gopher_dir. ...

Technical details

Protocol

The Gopher protocol is documented in RFC 1436. It is traditionally served on TCP port 70. The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. ... It has been suggested that this article or section be merged with Port numbers. ...

After the client has established a TCP connection with the server, it sends a line that contains the item selector, a string that identifies the document to be retrieved. The line is ended with a carriage return followed by a line feed (a "CR + LF" sequence). An empty line will select the default directory. The server then replies with the requested item and closes the connection.

A directory consists of a sequence of lines, each of which describes an item that can be retrieved. These lines are ended with "CR + LF". They consist of five fields, separated by TAB characters:

• item type character, which is usually one of the following:
  • 0 = plain text file
  • 1 = directory
  • 3 = error
  • 5 = ZIP archive
  • 7 = search server (returns a directory)
  • 9 = binary file
  • h = html file
  • i = informational text
  • I = image file
• description text
• item selector (typically a file-system pathname)
• domain name of the server on which the item resides
• port number of that server

Computer files can be divided into two broad categories: binary and text. ... In computing, a directory, catalog, or folder, is an entity in a file system which can contain a group of files and/or other directories. ... The ZIP file format is a popular data compression and archival format. ... A search engine or search service is a document retrieval system designed to help find information stored on a computer system, such as on the World Wide Web, inside a corporate or proprietary network, or in a personal computer. ... A Hexdump of a JPEG image. ... An example of HTML code with syntax highlighting and line numbers In computing, HyperText Markup Language (HTML) is a predominant markup language for the creation of web pages. ... A digital image is a representation of a two-dimensional image as a finite set of digital values, called picture elements or pixels. ...

URL links

Historically, to create a link to a Web server, "GET /" was used as the file to simulate an HTTP client request. John Goerzen created an addition ^[7] to the Gopher protocol, commonly referred to as "URL links", that allows links to any protocol that supports URLs. For example, to create a link to http://gopher.quux.org, the item type is "h", the description is arbitrary, the item selector is "URL:http://gopher.quux.org", and the domain and port are that of the originating Gopher server. For clients that do not support URL links, the server creates an HTML redirection page. John Goerzen is the President/chairman of the board, Software in the Public Interest, and a prominent member of the Internet Gopher community. ... A Uniform Resource Locator, URL (spelled out as an acronym, not pronounced as earl), or Web address, is a standardized address name layout for resources (such as documents or images) on the Internet (or elsewhere). ...

Gopher support in Web browsers

Mozilla Firefox 1.5 displaying the top-level menu of the Floodgap gopher server

Gopher support was disabled in Internet Explorer in June 2002 by a patch meant to fix a security vulnerability^[8] in the browser's Gopher protocol handler; however, it can be re-enabled by editing the Windows registry ^[9]. In Internet Explorer 7, Gopher support was removed on WinINET level. Image File history File links Download high-resolution version (762x623, 26 KB)[edit] Summary The gopher client in Firefox 1. ... Image File history File links Download high-resolution version (762x623, 26 KB)[edit] Summary The gopher client in Firefox 1. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... In computing, the Windows registry is a database which stores settings and options for the operating system for Microsoft Windows 32-bit versions, 64-bit versions and Windows Mobile. ... Internet Explorer, abbreviated IE or MSIE, is a proprietary web browser made by Microsoft and currently available as part of Microsoft Windows. ...

Other browsers, including Mozilla and AOL, still support the protocol, but incompletely — the most obvious deficiency is that they cannot display the informational text found on many Gopher menus. Konqueror needs a plugin^[10] to be installed for full Gopher support. Mozilla Firefox has full Gopher support as of release 1.5, and partial support in previous versions. The SeaMonkey Internet suite, successor of the Mozilla all-in-one suite, also supports Gopher fully, as does Camino, an open source browser based on Mozilla's engine. However, the most extensive gopher support is offered in Lynx, a text based browser. Mozilla logo Mozilla Firefox is a computer term that has had many different uses, though all of them have been related to Netscape Communications Corporation and its related application software. ... AOL LLC (formerly America Online, Inc) is an online service provider, bulletin board system, and media company operated by Time Warner. ... Konqueror is a file manager, web browser and file viewer, developed as part of the K Desktop Environment (KDE) by volunteers and runs on most Unix-like operating systems. ... Mozilla Firefox is a free, open source, cross-platform, graphical web browser developed by the Mozilla Corporation and hundreds of volunteers. ... It has been suggested that this article or section be merged with Mozilla Application Suite. ... Camino is a free, open source, graphical Web browser based on Mozillas Gecko layout engine and specifically designed for the Mac OS X family of operating systems. ... Lynx is a text-only web browser for use on cursor-addressable, character cell terminals. ...

The Safari Web browser does not support Gopher at all while Opera requires the use of a proxy such as Squid. Safari is a web browser developed by Apple Computer, Inc. ... Opera is an Internet suite which handles common internet-related tasks, including visiting web sites, sending and receiving e-mail messages, managing contacts, and online chat. ... Squid is a popular free software proxy server and web caching daemon, released under the GNU General Public License. ...

Gopher to HTTP gateways

Users of Web browsers that have incomplete or no support for Gopher^[11] can access content on Gopher servers via a server gateway that converts Gopher menus into HTML. One such server is at Floodgap.com. By default any Squid_cache proxy server will act as a Gopher to HTTP gateway. An example of HTML code with syntax highlighting and line numbers In computing, HyperText Markup Language (HTML) is a predominant markup language for the creation of web pages. ... Squid is a popular free software proxy server and web caching daemon, released under the GNU General Public License. ...

Some Gopher servers, like PyGopherd, also have built-in Gopher to HTTP interfaces. PyGopherd is a modern Internet Gopher server written in Python and is maintained by John Goerzen. ...

Related technology

The main Gopher search engine is Veronica. Veronica offers a keyword search of most Gopher server menu titles in the gopher web. A Veronica search produces a menu of Gopher items, each of which is a direct pointer to a Gopher data source. Currently, there is only one Veronica-2 server. Veronica is a search engine system for the Gopher protocol, developed in 1992 by Steven Foster and Fred Barrie at the University of Nevada. ...

GopherVR is a 3D variant of the original Gopher system. In 1995[1], the Gopher developers at the University of Minnesota released GopherVR. GopherVR was an enhanced version of the Unix and Macintosh gopher clients that included a 3D visualization tool for viewing resource collections as 3D scenes. ...

See also

• Veronica - the search engine system for the Gopher protocol, an acronym for "Very Easy Rodent-Oriented Net-wide Index to Computer Archives".
• Jughead - an alternative search engine system for the Gopher protocol.
• Gopher+ - extensions to the Gopher protocol
• HyTelnet - a similar mechanism for unifying Telnet-based interfaces
• Super Dimension Fortress - a non-profit organization which provides free Gopher access

Veronica is a search engine system for the Gopher protocol, developed in 1992 by Steven Foster and Fred Barrie at the University of Nevada. ... Jughead is a search engine system for the Gopher protocol. ... A search engine or search service is a document retrieval system designed to help find information stored on a computer system, such as on the World Wide Web, inside a corporate or proprietary network, or in a personal computer. ... Gopher+ are a fowards compatible enhancements to the RFC 1346 Gopher protocol. ... // History HyTelnet (sometimes rendered Hytelnet or HyTELNET) was an early attempt to create a universal or at least simpler interface for the various Telnet-based information resources available before the World Wide Web. ... TELNET is a network protocol used on the Internet or local area network LAN connections. ... The SDF logo, a decscope. ...

References and footnotes

1. ^ Google Groups archive of bit.listserv.cwis-l discussion
2. ^ Google Groups archive of comp.infosystems.gopher discussion
3. ^ http://www.funet.fi/pub/vms/networking/gopher/gopher-software-licensing-policy.ancient
4. ^ http://groups.google.com/groups?selm=1mj6cb$6gm@pith.uoregon.edu
5. ^ http://groups.google.com/groups?selm=36e4c2f1.10244576@nntp.best.ix.netcom.com
6. ^ ftp://boombox.micro.umn.edu/pub/gopher/gopher-software-licensing-policy.new
7. ^ http://gopher.quux.org/Archives/Mailing%20Lists/gopher/gopher.2002-02|/MBOX-MESSAGE/34
8. ^ Microsoft Security Bulletin MS02-047.
9. ^ This is achieved by adding the following registry entry: HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet SettingsEnableGopher = dword:00000001
10. ^ The kgopher KIO plugin can be downloaded from http://kgopher.berlios.de/.
11. ^ To determine whether a Web browser supports Gopher, compare the display of this gopher menu with the same menu produced by a Gopher to HTML gateway in the browser.

Konqueror is a file manager, web browser and file viewer, developed as part of the K Desktop Environment (KDE) by volunteers and runs on most Unix-like operating systems. ...

External links

• The Gopher Project (gopher link)
• The Gopher Project (web link)
• The state of Gopher support for common Web browsers
• List of Gopher servers (gopher link)

Standards

• The Gopher Protocol (RFC1436)
• Gopher+ Extensions
• URL links