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 the Hypertext Transfer Protocol (HTTP) The Gopher ecosystem is often regarded as the effective predecessor of the World Wide Web.
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.
More recent Gopher revisions and graphical clients added support for multimedia.
Gopher was preferred by many network administrators for using fewer network resources than Web services.
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.
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 :
- 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, such as searches.
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 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, to which CERN disclaimed ownership. 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 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.
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.
- 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.
- In November 2014 Veronica indexed 144 gopher servers, reflecting a small drop from 2012, but within these servers Veronica indexed approximately 3 million unique selectors.
- In March 2016 Veronica indexed 135 gopher servers, within which it indexed approximately 4 million unique selectors.
- In March 2017 Veronica indexed 133 gopher servers, within which it indexed approximately 4.9 million unique selectors.
- In May 2018 Veronica indexed 260 gopher servers, within which it indexed approximately 3.7 million unique selectors.
- In May 2019 Veronica indexed 320 gopher servers, within which it indexed approximately 4.2 million unique selectors.
- In January 2020 Veronica indexed 395 gopher servers, within which it indexed approximately 4.5 million unique selectors.
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 is designed to function and to appear much like a mountable read-only global (and software, such as gopherfs, is available that can actually mount a Gopher server as a resource).
At a minimum, whatever a person can do with data files on a CD-ROM, one can do 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.
The Gopher protocol was first described in .
The protocol is simple to negotiate, making it possible to browse without using a client.
A standard gopher session may therefore appear as follows:
Here, the client has established 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.
The server then replies with the requested item and closes the connection.
According to the protocol, before the connection is closed, the server should send a full-stop (i.e., a period character) on a line by itself.
However, as is the case here, not all servers conform to this part of the protocol and the server may close the connection without returning the final full-stop.
In this example, the item sent back is a gopher menu, a directory consisting of a sequence of lines each of which describes an item that can be retrieved.
Most clients will display these as hypertext links, and so allow the user to navigate through gopherspace by following the links.
All lines in a gopher menu are terminated by "CR + LF", and consist of five fields: the item type as the very first character (see below), the display string (i.e., the description text to display), a selector (i.e., a file-system pathname), host name (i.e., the domain name of the server on which the item resides), and port (i.e., the port number used by that server).
The item type and display string are joined without a space; the other fields are separated by the tab character.
Because of the simplicity of the Gopher protocol, tools such as netcat make it possible to download Gopher content easily from the command line:
The protocol is also supported by cURL as of 7.21.2-DEV.
The selector string in the request can optionally be followed by a tab character and a search string.
This is used by item type 7.
Gopher menu items are defined by lines of tab-separated values in a .
This file is sometimes called a gophermap.
Each tab-separated line (called a selector line) gives the client software a description of the menu item: what it is, what it's called, and where it leads.
The client displays the menu items in the order that they appear in the gophermap.
The first character in a selector line indicates the item type, which tells the client what kind of file or protocol the menu item points to.
This helps the client decide what to do with it.
The item type is followed by the user display string (a description or label that represents the item in the menu); the selector (a path or other string for the resource on the server); the hostname (the domain name or IP address of the server), and the network port.
The item type of 1 indicates that the resource is a Gopher menu.
The string "Floodgap Home" is what the user sees in the menu.
|Item type||User display string||Selector||Hostname||Port|
In a Gopher menu's source code, a one-character code indicates what kind of content the client should expect.
This code may either be a digit or a letter of the alphabet; letters are case-sensitive.
The technical specification for Gopher, , defines 14 item types.
A one-character code indicates what kind of content the client should expect.
Gopher client authors improvised item types h (HTML), i (informational message), and s () after the publication of .
Browsers like Netscape Navigator and early versions of Microsoft Internet Explorer would prepend the item type code to the selector as described in , so that the type of the gopher item could be determined by the url itself.
Most gopher browsers still available, use these prefixes in their urls.
|3||Error code returned by a Gopher server to indicate failure|
|4||BinHex-encoded file (primarily for Macintosh computers)|
|7||Gopher full-text search|
|+||Mirror or alternate server (for load balancing or in case of primary server downtime)|
|d||Doc. Seen used alongside PDF's and .DOC's|
|s||(especially the WAV format)|
|f F A B C D E G H J K L|
For example, to create a link to , the item type is h, the display string is the title of the link, the item selector is "URL:http://gopher.quux.org/", and the domain and port are that of the originating Gopher server (so that clients that do not support URL links will query the server and receive an HTML redirection page).
The master Gopherspace search engine is Veronica.
Veronica offers a keyword search of all the public Internet Gopher server menu titles.
A Veronica search produces a menu of Gopher items, each of which is a direct pointer to a Gopher data source.
GopherVR is a 3D virtual reality variant of the original Gopher system.
|First supported||Last supported|
|Present||Gopher-only browser for Windows, page cache, TFTP, G6 gopher protocol support|
|Browse||?||Present||This browser is for RISC OS|
|Camino||1.0||2.1.2||Always uses port 70.|
|Classilla||9.0||Present||Hardcoded to port 70 from 9.0–9.2; whitelisted ports from 9.2.1|
|Present||cURL is a command-line file transfer utility|
|ELinks||0.10.0||?||Offers support as a build option|
|Epiphany||?||2.26.3||Disabled after switch to WebKit|
with plug-in only
with plug-in only
|Requires Falkon ≥ 3.1.0 with both the KDE Frameworks Integration extension (shipped with Falkon ≥ 3.1.0) enabled and the (separate) kio_gopher plug-in ≥ 0.1.99 (first release for KDE Frameworks 5) installed|
|Google Chrome||With extension only||N/A||With Burrow extension|
|Internet Explorer||N/A||6||Support removed by MS02-047 from IE 6 SP1 can be re-enabled in the Windows Registry. Always uses port 70.|
|Internet Explorer for Mac||?||5.2.3||PowerPC-only|
|Konqueror||With plug-in only||?||Requires kio_gopher plug-in|
|Present||libwww is an API for internet applications|
|Line Mode Browser||Present|
|Mozilla Firefox||0.0||3.6||Built-in support dropped from Firefox 4.0 onwards; can be added back by installing one of the extensions by the Overbite Project|
|NetSurf||N/A||N/A||Under development, based on the cURL fetcher|
|OmniWeb||5.9.2||Present||First WebKit Browser to support Gopher|
|Opera||N/A||N/A||Opera 9.0 includes a proxy capability|
|Pavuk||?||Present||Pavuk is a web mirror (recursive download) software program|
|SeaMonkey||1.0||2.0.14||Built-in support dropped from SeaMonkey 2.1 onwards; can be added back by installing one of the extensions by the Overbite Project|
|WebPositive||?||Present||WebKit-based browser used in the Haiku operating system|
Browsers that do not natively support Gopher can still access servers using one of the available Gopher to HTTP gateways.
Gopher support was disabled in Internet Explorer versions 5.x and 6 for Windows in August 2002 by a patch meant to fix a security vulnerability in the browser's Gopher protocol handler to reduce the attack surface which was included in IE6 SP1; however, it can be re-enabled by editing the Windows registry.
Gopher browser extensions
- OverbiteWX redirects gopher:// URLs to a proxy;
- OverbiteNX adds native-like support;
- for Firefox up to 56.*, and equivalent versions of SeaMonkey, OverbiteFF adds native-like support.
OverbiteWX includes support for accessing Gopher servers not on port 70 using a whitelist and for CSO/ph queries.
OverbiteFF always uses port 70.
It redirects gopher:// URLs to a proxy.
In the past an Overbite proxy-based extension for these browsers was available but is no longer maintained and does not work with the current (>23) releases.
For Konqueror, Kio gopher is available.
Gopher clients for mobile devices
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, mobile adaptations of HTML and XML and other simplified content have proven more popular.
Other Gopher clients
Gopher popularity was at its height at a time when there were still many equally competing computer architectures and operating systems.
As a result, there are several Gopher clients available for Acorn RISC OS, AmigaOS, Atari MiNT, CMS, DOS, classic Mac OS, MVS, NeXT, OS/2 Warp, most UNIX-like operating systems, VMS, Windows 3.x, and Windows 9x.
Gopher to HTTP gateways
Users of Web browsers that have incomplete or no support for Gopher can access content on Gopher servers via a server gateway or proxy server that converts Gopher menus into HTML; known proxies are the Floodgap Public Gopher proxy and Gopher Proxy.
Squid Proxy software gateways any gopher:// URL to HTTP content, enabling any browser or web agent to access gopher content easily.
Because the protocol is trivial to implement in a basic fashion, there are many server packages still available, and some are still maintained.
|Server||Developed by||Latest version||Release date||License||Written in||Notes|
|Rob Linwood||1.0.1||22 April 2004||MIT||Java|
|Timm Murray||0.1||26 March 2004||GPL||Perl||Apache 2 plugin to run Gopher-Server.|
|Charles Childers||2017.4||9 October 2017||ISC||Forth|
|Bucktooth||Cameron Kaiser||0.2.9||1 May 2011||Floodgap Free Software License||Perl|
|SSS8555||0.777||7 July 2020||Perl||with G6 extention and TFTP|
|Michael Lazar||2.2.1||11 April 2020||GPLv3||Python|
|Quinn Evans||0.0.1||10 August 2015||2-clause BSD||Common Lisp|
|Christoph Lohmann||0.34||13 March 2019||MIT||C|
|?||2.25-20020226||26 February 2002||GPL||C|
|Sean MacLennan||1.2||8 October 2010||GPLv2||C|
|Geoff Sevart||1.07||8 July 2013||Freeware||.NET 3.5 (Win32/Win64)||Version 1.06 of 26 August 2010 is available from .|
|Timm Murray||0.1.1||26 March 2004||GPL||Perl|
|Kim Holviala and others||3.1||14 November 2019||BSD||C|
|Guillaume Duhamel||0.2.3||29 March 2012||GPL||C|
|?||0.5||30 December 2012||GPLv3||FreeBASIC||Version 0.4 is available from .|
|Aaron W. Hsu||8.0||20 June 2011||ISC||Scheme|
|Mate Nagy||1.1||29 January 2018||GPLv3||C|
|Mateusz Viste||1.0.12||7 July 2019||GPLv3||C|
|dotcomboom||1.1||16 May 2020||BSD 2-Clause||Python||Python-based Gopher library with both server and client support|
|PyGopherd||John Goerzen||184.108.40.206||14 February 2017||GPL||Python|
|Adam Gurno||0.3.5||7 August 2001||GPLv2||Python||Development stopped as of 17 April 2003|
|Salvatore Sanfilippo||6.0.9||26 October 2020||BSD 3 Clause||C|
|Lukas Epple||0.2.1.2||13 May 2020||GPL||Haskell|
|Nathaniel Leveck||0.0.1||15 January 2020||GPL||FreeBASIC|
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Gopher (protocol).