Contents
These are most recent changes.
- NCSA don't serve CERN's browser by FTP
- Mosaic is no longer beta
This is an introduction to the World-Wide Web project, describing the
concepts, software and access methods. It is aimed at people who know
a little about navigating the Internet, but want to know more about
WWW specifically. If you don't think you are up to this level, try Ed
Krol's "The Whole Internet".
This informational document is posted to news.answers, comp.infosystems.gopher, comp.infosystems.wais and alt.hypertext on the 1st and 15th of
every month (please allow a day or two for it to propagate to your
site). The latest version is always available on the web as http://www.vuw.ac.nz:80/non-local/gnat/www-faq.html
(see the section titled "What is a URL?" to
understand what this means).
The most recently posted version of this document is kept on the news.answers
archive on rtfm.mit.edu in /pub/usenet/news.answers/www-faq
(the URL for this is file://rtfm.mit.edu/pub/usenet/news.answers/www-faq).
For information on FTP, send e-mail to
mail-server@rtfm.mit.edu with "send
usenet/news.answers/finding-sources" in the body, instead of
asking me.
Nathan
Torkington maintains this document. Feedback about it is to be
sent via e-mail to Nathan.Torkington@vuw.ac.nz
In all cases, regard this document as out of date. Definitive
information should be on the web, and static versions such as this
should be considered unreliable at best.
WWW stands for the "World Wide Web". The WWW project, started and
driven by CERN (the European
Laboratory for Particle Physics), seeks to build a distributed
hypermedia system.
To access the web, you run a browser
program. The browser reads documents, and can fetch documents
from other sources. Information providers set up hypermedia
servers which browsers can get documents from.
The browsers can, in addition, access files by FTP, NNTP (the Internet news protocol), gopher
and an
ever-increasing range of other methods. On top of these, if the
server has search capabilities, the browsers will permit searches
of documents and databases.
The documents that the browsers display are hypertext documents.
Hypertext is text with pointers to other text. The browsers let you
deal with the pointers in a transparent way -- select the pointer, and
you are presented with the text that is pointed to.
Hypermedia is a superset of hypertext -- it is any medium with
pointers to other media. This means that browsers might not display a
text file, but might display images or sound or animations.
URL stands for "Uniform Resource Locator". It is a draft standard for
specifying
an object on the Internet, such as a file or newsgroup.
URLs look like this:
- file://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
- file://wuarchive.wustl.edu/mirrors
- http://info.cern.ch:80/default.html
- news:alt.hypertext
- telnet://dra.com
The first part of the URL, before the colon, specifies the access
method. The part of the URL after the colon is interpreted specific
to the access method. In general, two slashes after the colon
indicate a machine name (machine:port is also valid). For more
information, see
You have two options -- either use a browser that can be telnetted to,
or use a browser on your machine.
An up-to-date list of these is available on the Web as http://info.cern.ch/hypertext/WWW/FAQ/Bootstrap.html
and should be regarded as an authoritative list.
- info.cern.ch
- No password is required. This is in
Switzerland, so continental US users might be better off using a
closer browser.
- ukanaix.cc.ukans.edu
-
A full screen browser "Lynx" which requires a vt100 terminal.
Log in as www.
- eies2.njit.edu
-
(or telnet 128.235.1.43) Log in as www. A full-screen browser
in New Jersey Institute of Technology. USA.
- vms.huji.ac.il
-
(IP address 128.139.4.3). A dual-language Hebrew/English
database, with links to the rest of the world. The line mode
browser, plus extra features. Log in as www. Hebrew
University of Jerusalem, Israel.
- sun.uakom.cs
-
Slovakia. Has a slow link, only use from nearby.
- info.funet.fi
-
(or telnet 128.214.6.100) Not available when tested in
O29-Oct-92. (FINLAND)
5.2 Obtaining browsers
The preferred method of access of the Web is to run a browser
yourself. Browsers are available for many platforms, both in source
and executable forms. Here is a list generated from the authoritative
list, http://info.cern.ch/hypertext/WWW/Clients.html ...
- Terminal based browsers
-
- Line Mode Browser
-
This program gives W3 readership to anyone with a dumb
terminal. A general purpose information retrieval tool.
- "Lynx" full screen browser
-
This is a hypertext browser for vt100s using full screen,
arrow keys, highlighting, etc.
- NJIT's Browser
-
Assumes a character-grid terminal with cursor addressing,
and provides a full-screen interface to the web.
- Tom Fine's perlWWW
-
A tty-bbased browser written in perl.
- Graphic User Interfaces
-
- XMosaic
-
Browser using X11/Motif. Works well. This is the most
polished browser.
- Macintosh Browser
-
Browser for the Macintosh. (Alpha.)
- "Cello" PC/Windows client
-
Browser for windows. (Not yet released)
- "Erwise"
-
Browser for X/Motif. (Unsupported).
- "ViolaWWW" Browser for X11
-
Browser for X11. (Beta, unsupported)
- tkWWW Browser
-
Browser for X11. (Beta).
- MidasWWW Browser
-
WWW browser for X/Motif. (Beta, works well.)
- Browser-Editor on the NeXT
-
A browser/editor for NeXTStep. Allows wysiwyg hypertext
editing. Requires NeXTStep 3.0
- Unreleased
-
- Browser on CERNVM
-
A full-screen browser for VM. Nonexistant. Use the line
mode www.
- Dave Ragget's Browser
-
Unreleased. For X11, (later PC?)
Information providers run programs that the browsers can obtain
hypertext from. These programs can either be WWW servers that
understand the HyperText Transfer Protocol HTTP (best if you are
creating your information database from scratch), "gateway" programs
that convert an existing information format to hypertext, or a
non-HTTP server that WWW browsers can access -- anonymous FTP or
gopher, for example.
If you only want to provide information to local users, placing your
information in local files is also an option. This means that there
would be no off-machine access.
CERN's server is available for anonymous FTP from info.cern.ch and
many other places. Use archie to search for
"www" or "WWW" to find copies close to you. NCSA have their own
server, for FTP from ftp.ncsa.uiuc.edu.
See http://info.cern.ch/hypertext/WWW/Daemon/Overview.html for more
information on writing gateways and for servers in general.
While all three of these information presentation systems are
client-server based, they differ in terms of their model of data. In
gopher, data is either a menu, a document, an index or a telnet
connection. In WAIS, everything is an index and everything that is
returned from the index is a document. In WWW, everything is a
(possibly) hypertext document which may be searchable.
In practice, this means that WWW can represent the gopher (a menu is a
list of links, a gopher document is a hypertext document without
links, searches are the same, telnet sessions are the same) and WAIS
(a WAIS index is a searchable page, returning a document with no
links) data models as well as providing extra functionality.
The principal difference between the three systems, it turns out, is
deployment. WWW does not have as large a user base as gopher, mainly
because of the small number of WWW browsers that are out. This is
changing as WWW reaches critical mass (usage of the server at CERN
doubles every 4 months -- twice the rate of Internet expansion).
Currently accessable through the web:
- anything served through gopher
- anything served through WAIS
- anything on an FTP site
- anything on Usenet
- anything accessable through telnet
- anything in hytelnet
- anything in hyper-g
- anything in techinfo
- anything in texinfo
- anything in the form of man pages
- sundry hypertext documents
One of the few limitations of the current networked information
systems is that there is no simple way to find out what has changed,
what is new, or even what is out there. As a result, a definitive
list of the web's contents is impossible at this moment.
To find out more, use the web.