In February of 1993, the University of Minnesota announced that it would charge licensing fees for the use of its implementation of the Gopher server.[3] As a consequence of this some users suspected that a licensing fee would also be charged for independent implementations.[4][5] In contrast, no such limitation has yet been imposed on the World Wide Web. The University of Minnesota eventually re-licensed its Gopher software under the GNU GPL.[6]
- Gopher Client functionality was quickly duplicated by early Web browsers, such as Mosaic. Furthermore, the commercial friendliness of the World Wide Web, with its integration of text and graphics, made Gopher less appealing to marketing personnel.[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. Graphic Designers did not like the artificial distinction between menu and fixed document in the Gopher system, and found the Web's open-ended flexibility better suited for constructing interrelated sets of documents and interactive applications.[citation needed]
Availability of Gopher today
As of 2007, there are fewer than 100 gopher servers indexed by Veronica-2.[7] Many of them are owned by universities in various parts of the world. Most of them are neglected and rarely updated except for the ones run by enthusiasts of the protocol. A handful of new servers are set up every year by hobbyists - 30 have been set up and added to Floodgap's list since 1999[8] and possibly some more that haven't been added.
Some have suggested that the bandwidth-sparing simple interface of Gopher would be a good match for mobile phones and Personal digital assistants (PDAs),[9] but so far, the Web-fixated 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.
Gopher support in Web browsers
Gopher support was disabled in Internet Explorer versions 5.* and 6 for Windows in June 2002 by a patch meant to fix a security vulnerability in the browser's Gopher protocol handler; however, it can be re-enabled by editing the Windows registry.[10] In Internet Explorer 7, Gopher support was removed on the WinINET level.[11] Internet Explorer for Mac (only on PowerPC architecture and in End-of-life) still supports Gopher. Internet Explorer is hard coded to work on Port 70.
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 to be installed for full Gopher support, such as kio_gopher. 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, a browser based on Mozilla's engine. Such Mozilla based browsers are able to display embedded images from a gopher server on an HTTP-based HTML document and follow download links to a gopher server. However, the most extensive gopher support is offered in Lynx, a text based browser.
The Safari and Opera web browsers, (although Opera 9.0 includes a proxy capability) do not support Gopher at all.
Gopher Clients
Gopher was at its height of popularity during a time when there were still many equally competing computer architectures and operating systems. As such, there are several Gopher Clients available for Acorn RISC OS, AmigaOS, Atari MiNT, CMS, DOS, MacOS 7x, MVS, NeXT, OS/2 Warp, most UNIX-like operating systems, VMS, Windows 3x, and Windows 9x. There are several Gopher Clients designed for 3D visualization, and even a Gopher Client MOO object. The majority of these clients are hard coded to work on Port 70.
Gopher to HTTP gateways
Users of Web browsers that have incomplete or no support for Gopher[12] 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.
Some Gopher servers, such as GN and PyGopherd, also have built-in Gopher to HTTP interfaces.
Gopher characteristics
In characteristic, Gopher functions and appears 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 a person can do with data files on a CD-ROM, they 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.
Technical details
Protocol
The Gopher protocol was first described in INFORMATIONAL RFC 1436. IANA has assigned TCP port 70 to the Gopher protocol.
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:
- description text
- item selector (typically a file-system pathname)
- domain name of the server on which the item resides
- port number of that server
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 [13] 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.
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.
GopherVR is a 3D variant of the original Gopher system.
Gopher server software
See also
- Veronica - the search engine system for the Gopher protocol, an acronym for "Very Easy Rodent-Oriented Net-wide Index to Computer Archives".
- Jugtail - an alternative search engine system for the Gopher protocol. Jugtail was formerly known as Jughead.
- Gopher+ - early proposed extensions to the Gopher protocol
- Super Dimension Fortress - a non-profit organization which provides free Gopher hosting
- Phlog - The gopher version of a weblog
References and footnotes
- ^ Google Groups archive of bit.listserv.cwis-l discussion
- ^ Google Groups archive of comp.infosystems.gopher discussion
- ^ http://www.funet.fi/pub/vms/networking/gopher/gopher-software-licensing-policy.ancient
- ^ Google Groups
- ^ http://groups.google.com/groups?AMITselm=36e4c2f1.10244576@nntp.best.ix.netcom.com
- ^ gopher://home.jumpjet.info/00\Begin_Here\References\License\gopher-software-licensing-policy_new.txt
- ^ Kaiser, Cameron (2007-03-19). Down the Gopher Hole. TidBITS. Retrieved on 2007-03-23.
- ^ gopher://gopher.floodgap.com/1/new
- ^ Wired News: Gopher: Underground Technology
- ^ Microsoft Security Bulletin MS02-047. Microsoft (2003-02-28). Retrieved on 2007-03-23.
- ^ Release Notes for Internet Explorer 7. Microsoft (2006). Retrieved on 2007-03-23.
- ^ 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.
- ^ http://gopher.quux.org/Archives/Mailing%20Lists/gopher/gopher.2002-02|/MBOX-MESSAGE/34
External links
Standards
ca:Gopher
da:Gopher de:Gopher es:Gopher fr:Gopher gl:Gopher he:גופר ko:고퍼 프로토콜 hr:Gopher it:Gopher (informatica) lt:Gopher nl:Gopher ja:Gopher pl:Gopher pt:Gopher ru:Gopher (сетевой протокол) sq:Shërbimi Gofer simple:Gopher (protocol) sk:Gopher sl:Gopher fi:Gopher sv:Gopher tr:Gopher uk:Gopher
