Figure 2-1 WWW Client-Server Architecture.
Distributed: information on WWW may be located on computer systems around the world.
Multimedia: the information held on WWW can include text, graphics, sound and even video.
Hypertext: access to the information is available using hypertext techniques, which typically involve using a mouse to select highlighted phrases or images. Once a phrase or image is selected it can result in information being retrieved from around the world.
The World-Wide Web was initially developed by Tim Berners-Lee and Robert Cailliau of CERN Laboratories, Geneva to provide an infrastructure for particle physicists throughout Europe to share information. Since the physicists were located in various organisations and used a variety of computer systems and applications software (including various word processing and text markup programs for producing reports) the World-Wide Web was developed using the client-server architecture, which ensured cross-platform portability.
Figure 2-1 WWW Client-Server Architecture.
The end user accesses the World-Wide Web using a browser client, typically on a desktop machine such as a PC, Macintosh or Unix workstation. The client will display hypertext links in some manner, such as underlining the links. Selecting a link (by clicking a mouse button with a graphical client, typing the number following the link using a simple text-based client or using speech or foot pedals, for example, with browsers for disabled users) to send a request over the network (which could be a local network, a national network such as JANET, or over the global network which can be referred to as the Internet). The request is sent to a World-Wide Web server, which typically runs on a powerful computer system. The server will retrieve the file which has been requested and deliver it to the client.
Once the client has started to retrieve the file it can display it on the local machine. If the client cannot display the file (many clients, for example, cannot view video clips) the client can pass the file on to an external viewer which can process the file.
This is a very simple overview of the WWW client-server architecture. Many other features are available: for example the server could send a message to the client, saying that the user is not authorised to access the file. However an understanding of this model will help you to see how the WWW can develop.
telnet telnet.w3.org
from a computer system which runs the telnet software. An example of use of the CERN command line browser is illustrated below.
telnet telnet.w3.org
Welcome to the World-Wide Web
THE WORLD-WIDE WEB
This is just one of many access points to the web, the universe of
information available over networks. To follow references, just type the
number then hit the return (enter) key.
The features you have by connecting to this telnet server are very
primitive compared to the features you have when you run a W3 "client"
program on your own computer. If you possibly can, please pick up a client
for your platform to reduce the load on this service and experience the
web in its full splendor.
For more information, select by number:
A list of available W3 client programs[1]
Everything about the W3 project[2]
Places to start exploring[3]
The First International WWW Conference[4]
This telnet service is provided by the WWW team at the European Particle
Physics Laboratory known as CERN[5]
[End]
1-5, Up, Quit, or Help:
Figure 2-2 The CERN Command Line Browser.Notice that in the CERN command line browser in order to select a hypertext link you need to type the number which follows the link.
The CERN command line browser is a very simple client. The first WWW browser was developed by Tim Berners-Lee, the father of the World-Wide Web, for the NeXT system. However the NeXT hardware was not a commercial success and is no longer manufactured. One of the earliest graphical browsers was the Viola client which was developed for the X windows environment. Viola is illustrated in Figure 2-3.
Figure 2-3 The Viola Client.
Notice that in the Viola client the hypertext links are identified by the use of underlining.
Since CERN's remit was research in particle physics the WWW development team realised that they needed to involve other organisations in WWW development work. The involvement of NCSA in the WWW development programme resulted in the NCSA Mosaic For X, which was released in early 1993. An illustration of a pre-release version of Mosaic For X is shown in Figure 2-5.
Figure 2-5 A Pre-release Version Of NCSA Mosaic For X.
As can be seen from Figure 2-5 NCSA Mosaic For X provides access to a number of types of resources, including WAIS, Gopher, FTP, Usenet, Hytelnet, TeXinfo, X.500 and Whois resources. NCSA Mosaic was developed by a group of programmers at NCSA led by Marc Andreessen. NCSA Mosaic For X became such a success because:
Figure 2-6 Example of Scientific Information Held At CERN.
Figure 2-7 The Honolulu Community College CWIS.
Figure 2-8 A Distributed Teaching Application.
Figure 2-9 University of Leeds Prospectus Information.
Figure 2-10 The Vatican Exhibition.
Figure 2-11 A Commercial Application On WWW.
Figure 2-12 The CCTA Government Information Service.
Browser: An interactive program which is used to access information held on the World-Wide Web.
Client: Often used as a synonym for browser. A client is the software which normally runs on the local desktop machine (such as a PC, Apple Macintosh or Unix workstation). The client sends requests to the server software.
Server: Software which is used to deliver information to a client. Note that this term can also refer to the computer system on which the server software is running.
URL: Uniform Resource Locator. Can be regarded as the address of a file on the World-Wide Web. It includes the protocol (rules) for retrieving the file, the domain (name) of the computer system on which the server software runs and the file name to be retrieved. For example the URL http://info.cern.ch/hypertext/WWW/TheProject.html uses the http protocol to retrieve the file TheProject.html in the directory /hypertext/WWW from the computer called info.cern.ch
HTML: Hypertext Markup Language. The native language for documents held on the World-Wide Web. HTML is an SGML (Standard Generalised Markup Language) application.
HTTP: Hypertext Transport Protocol. The protocol (set of rules) used to define the communications between the client and WWW server software.
Note that these terms are, for reasons of clarity, in some cases over-simplified.
These browsers can be accessed by giving the command telnet address (for example telnet dir.mcc.ac.uk) In some cases you will automatically be logged in, in other cases you must enter a username (which is often lynx).
An example of the use of the telnet browser at the Radcliffe Science Library at Oxford University is illustrated in Figure 3-1.
telnet rsl.ox.ac.uk
Radcliffe Science Library & Bodleian Library WWW Server (p1 of 6)
RADCLIFFE SCIENCE LIBRARY & BODLEIAN LIBRARY WWW SERVER
UNIVERSITY OF OXFORD
[IMAGE]
Welcome! At present this WWW server is still feeling its way. This
page is intended primarily as a starting point for Oxford users
wishing to explore Internet services and information sources. From
this home page you can also access some of our Local WWW applications
which are for the most part still under development. For newcomers to
the Web, one good introduction is Entering the World-Wide-Web: A Guide
to Cyberspace by Kevin Hughes. Another is CERN's WWW FAQ (list of
Frequently Asked Questions).
Apologies to our regular Lynx users. We have phased out the old Lynx
opening page and you will now commence with this one. If you would
like to voice your opinions or your feelings, please feel free to use
the comments form below.
________________________________________________________________
-- press space for more, use arrow keys to move, '?' for help, 'q' to quit
Figure 3-1 The Client At Radcliffe Science Library.It should be noted that the organisations running these publicly available clients do not guarantee to provide the service on a long term basis.
Lynx has been ported to the MS DOS environment. DosLynx, as the implementation is known, will run on a PC with 512 K of RAM, running MS DOS 3 or later. It provides access to the World-Wide Web from an entry level PC which has the appropriate networking capability. DosLynx is illustrated in Figure 3-2.
Figure 3-2 DOS Lynx.
The DosLynx software is available at the URL ftp://ftp2.cc.ukans.edu/pub/WWW/DosLynx/
Details of the system requirements for DosLynx are available at the URL ftp://ftp2.cc.ukans.edu/pub/WWW/DosLynx/readme.htm A Listserv mailing list exists at the address DosLynx-Dev@ukanaix.cc.ukans.edu for the distribution of DosLynx related information, updates and development discussions. To subscribe send an email request to listserv@ukanaix.cc.ukans.edu to be added to the list. All new releases will be announced on this list.
Figure 3-3 NCSA Mosaic For X.
Figure 3-4 NCSA Mosaic For Windows and the Macintosh.
Further information about NCSA Mosaic For Windows is available at the URL http://www.ncsa.uiuc.edu/SDG/Software/WinMosaic/HomePage.html Further information about NCSA Mosaic For the Macintosh is available at the URL http://www.ncsa.uiuc.edu/SDG/Software/XMosaic/
Figure 3-5 The Cello Browser.
Figure 3-6 The WinWeb and MacWeb Browsers.
Figure 3-7 The Netscape Browser for Windows and the Macintosh.
Figure 3-8 The Air Mosaic Browser For Windows.
Figure 3-9 The GWIS Browser For X Windows.
Figure 3-10 The Warp OS/2 Browser.
Figure 3-11 The Arena Browser.
Another list, which includes a brief summary of known bugs. is available at the URL http://www.hotwired.com/browsers.html
A third list is available at the URL http://www.charm.net/~web/Vlib/Users/Clients.html
Perhaps the only conclusion to be made at this point is that academic institutions should avoid being locked in to a particular browser.
A simple HTML document is illustrated in Figure 4-1.
Figure 4-1 A Simple HTML Document.<TITLE>The World-Wide Web</TITLE> <H1>About The World-Wide Web</H1> <P>The World-Wide Web is a <EM>distributed multimedia hypertext</EM> system.</P>
Structural elements in the document are identified by start and end tags. For example the <TITLE> and </TITLE> tag is used to specify the title of the document, which is often displayed by a client. The <H1> and </H1> tag is used to define the first level heading. Clients will normally display headers differently from the body text: for example, a graphical client could display the header using a larger or different font, whereas a text-based client could display a header as centred text or in all capitals.
Figure 4-1 also illustrates the <EM> container. Text held in the container (which is defined by the <EM> start tag and the </EM> end tag) will be emphasised in some way. A graphical browser could render the emphased text by displaying it in italics, whereas a browser with audio capabilities for the visually impaired could render the emphasis by a change in the tone of the voice output.
Figure 4-1 also shows the paragraph container. It is important to understand that the <P> tag is part of a paragraph container and is no longer a paragraph separator (as many people mistakenly believe). If the </P> is not used the existence of the next <P> tag will imply a </P>. In future versions of HTML it will be possible to specify paragraph attributes: for example <P ALIGN=Centred>.
Although browsers will display the HTML document shown in Figure 4-1, for reasons of performance and upwards compatibility it is strongly recommended that HTML documents contain additional elements including the <HTML>, <HEAD> and <BODY> tags, as shown in Figure 4-2.
<HTML> <HEAD> <TITLE>The World-Wide Web</TITLE> </HEAD> <BODY> <H1>About The World-Wide Web</H1> <P>Information about the World-Wide Web is available <A HREF="http://info.cern.ch/hypertext/WWW/TheProject.html"> at CERN</A>.</P> </BODY> </HTML>Figure 4-2 A Simple HTML Document.
The <HTML> container is used to define the extent of the HTML document. Within the HTML document there are two other containers: <HEAD> and <BODY>. The <HEAD> container provides information about the document itself. This can include the title of the document (as illustrated) copyright information, keywords and expiry dates (for use by caching software). It is important to make use of the tag since, for example, an automatic indexing program which wishes to index the title of HTML documents can parse only the information contained in the container. If the container is not present the entire document may have to be parsed, which will place unnecessary extra load on the server.
Figure 4-2 also illustrates the use of the anchor <A> container. This tag is used to provide hypertext links. In the example the text at CERN which is contained between the <A> and </A> tags will be highlighted in some way by the browser. Selecting this highlighted phrase will cause the client to send a request for http://info.cern.ch/hypertext/WWW/TheProject.html This request will use the http protocol and will be sent to the server running on the system at info.cern.ch
Figure 4-3 HTML Assistant.
Figure 4-4 HTML HyperEdit
Figure 4-5 HTMLEd.
Word processing tools have the advantage that they provide a consistent environment for existing users of word processors. However they do have their disadvantages. Because they are normally implemented as macros, they can be very slow, especially when used with large or complicated documents. There is also a danger that HTML markup which is embedded as hidden text could cause conflicts with other word processing tools if, for example, the word processed document was used by other users.
Figure 4-6 The GT_HTML Macro.
Figure 4-7 The CU_HTML Macro.
Figure 4-8 The ANT_HTML Macro.
Figure 4-9 Editing A Document From Arena.
Figure 4-10 A Document Converted Using LaTeX2html.
LaTeX2html is available at the URL ftp://src.doc.ic.ac.uk/packages/WWW/tools/translators/latex2html Further information is available at the URL http://cbl.leeds.ac.uk/nikos/doc/www94/www94.html
RTFtohtml is available as a command line tool for a number of Unix platforms. In addition an Apple Macintosh implementation is available. A beta version of an MSDOS implementation was announced in November 1994.
An extension of the RTFtohtml program is known as RTFtoweb. This provides a number of additional features, including creation of hypertext links at user defined section breaks. Figure 4-11 illustrates a document on Exploring The World-Wide Web Using Mosaic For Windows which is available at the URL http://www.leeds.ac.uk/ucs/docs/tut50/tut50.html
Figure 4-11 Document Converted Using RTFtoweb.
In Figure 4-11 it should be noted that the document is automatically split into a number of files. A hypertext table of contents is automatically generated. Chevrons (>> and <<) are also generated automatically which can be used to move to the next or previous section.
Further information about RTFtohtml is available at the URL ftp://ftp.cray.com/src/WWWstuff/RTF/rtftohtml_overview.html The software is available at the URL ftp://ftp.cray.com/src/WWWstuff/RTF/latest/ In the UK it is available at the URL ftp://src.doc.ic.ac.uk/packages/WWW/tools/translators/rtftohtml RTFtoweb is available at the URL ftp://ftp.rrzn.uni-hannover.de/pub/unix-local/misc/rtftoweb/html/rtftoweb.html
A number of HTML validation tools are available which can validate HTML documents. A number of popular tools are described below.
Figure 4-12 HoTMetaL.
HoTMetaL is available for the X and Microsoft Windows platforms. Two versions of the software are available: a public domain version and a licensed version. HoTMetaL Pro, the licensed version, can be used to import and validate an existing document. The public domain version will give an error and refuse to load a document which contains invalid HTML.
HoTMetaL is available at the URL ftp://src.doc.ic.ac.uk/packages/WWW/Mosaic/html/hotmetal
Figure 4-13 HTML Validation Service.
A variation on this service is available at the URL http://www.cc.gatech.edu/grads/j/Kipp.Jones/HaLidation/validation-form.html
These services make of the sgmls validation program.
The software can be installed on your local Unix system. It is available at the URL ftp://ftp.hal.com/pub/CGI/check-html.tar.Z
Figure 4-14 Installing The Check_HTML Script.
Support Who wrote the software - an experienced software developer or a student as part of a computer project? Will the software continue to be developed and supported?
Quality Does the software produce valid HTML?
Functionality What facilities does the software provide?
Other Issues If the software is based on a word processing package, what happens if the word processed document needs to be used by another word processor?
A review of Microsoft Windows HTML authoring tools is available at the URL http://werple.apana.org.au/~gabriel/html-editors/index.html
A list of HTML tools is available at the URL http://info.cern.ch/hypertext/WWW/Tools/Filters.html
Dan Connolly's HTML Design Notebook is available at the URL http://www.hal.com/%7Econnolly/html-design.html
The HTML specification is available at the URL http://www.hal.com/%7Econnolly/html-spec.html
<IMG SRC="portrait.gif">
The full syntax for the <IMG> tag is:
<IMG SRC="source file" ALT="textual description" ALIGN="option">
The SRC attribute is used to specify the URL of the graphical file. At the time of writing graphical files should normally be in GIF format, although support for other graphical file formats may be available in certain browsers. The SRC attribute is mandatory.
The ALT attribute is used to specify text which should be displayed by a browser which cannot display graphics, or a browser which has the display of inline images option switched off. Use of the ALT attribute is highly recommended.
The ALIGN attribute can take the values TOP, MIDDLE or BOTTOM. It is used to define whether the top, middle or bottom of the graphic should be aligned with the text. Use of the ALIGN attribute is optional.
One common use of the <A> tag is to provide a link to a large colour graphic from a small thumbnail image. For example:
<A HREF="full-image.jpeg"><IMG SRC="thumbnail.gif" ALT="Portrait of John Smith"></A>
It is also possible to use this technique to provide links from thumbnail images to video clips. For example:
<A HREF="fluidflow.mpeg"><IMG SRC="fluidflow.thumb.gif" ALT="Video clip of fluid flow"></A>
An active map can be specified as shown in the HTML document below.
Please select an area of the xray showing cancerous growths.
<A HREF="cgi-bin/htimage/xray.config">
<A IMG SRC="xray.gif" ISMAP></A>
Figure 5-1 HTML Document Containing Markup For An Active Map.
The file xray.config will contain the coordinates of regions in the image, as illustrated below.
default error.html
rectangle (100,100) (500,500) cancer.html
circle (50,50) 25 homepage.html
Figure 5-2 Configuration File For Active Map.
When the user clicks on an area of the image the coordinates are sent to the cgi-bin/htimage CGI program. The name of the configuration file for the image (in this case (xray.config) is also sent to this program. The htimage program will then retrieve the HTML document specified in the confuguration file. If, for example, the user has clicked in a circle defined by the centre at position 50,50 with a radius of 25, the file homepage.html will be sent to the browser. If the user has clicked in a rectangle with vertices at the position 100,100 and 500,500 the file cancer.html will be sent to the browser.
Figure 5-3 MapEdit.
Figure 5-4 Paintshop Pro.
The image being manipulated by Paintshop Pro contains information for 256 colour (as shown in the bottom left of the screen). The colour depth of the image should be reduced to decrease the size of the file to an appropriate level (e.g. a line drawing should not contain 256 colours), and thus reduce the network traffic when the image is retrieved on WWW.
San Diego Supercomputer Center's imtools package converts many file formats, including GIFs.
ImageMagick is a multi-purpose raster converter and manipulation package. The convert program handles many file formats including GIF. The software is available at the URL ftp://ftp.x.org/contrib
Graphics Workshop from Alchemy Mindworks is a DOS package for converting graphical files.
Before making use of graphics you should consider the following points:
http://www.leeds.ac.uk/ucs/people/BKelly/uniras94/uk_logos.html
Figure 5-5 UK University Logos.
This page contains pointers to logos on institutional UK university WWW servers. Details of the numbers of colours and the file size are also provideed.
A good example of use of graphics is the Xerox Parc Map viewer which is available at the URL http://pubweb.parc.xerox.com/map
Figure 6-1 A Collection Of WWW Search Engines.
A collection of WWW search engines is available at the URL http://cui.unige.ch/meta-index.html Some of the main searching tools are listed below:
There are a number of problems with this approach to global indexing:
A list of robots is kept at the URL http://web.nexor.co.uk/mak/doc/robots/active.html
Further information about Aliweb is available at the URL http://web.nexor.co.uk/aliweb/doc/aliweb.html The paper ALIWEB - Archie-Like Indexing In the Web, which was presented at the WWW 94 conference in CERN, is available at the URL http://web.nexor.co.uk/mak/doc/aliweb-paper/paper.html
The command:
waisserver -p 210 -d /apps/info/WWW/WAIS
is used to start the WAIS server software. The -p 210 argument specifies the name of the port on which the server runs while the -d argument gives the name of the directory which will contain WAIS databases. Note that since the WAIS server will normally be running continuously it will normally be initiated by the system administrator.
Newsletters are indexed by giving the command
waisindex -export -d /apps/info/WWW/ucs/newsletter/wais-sources/computing-service-newsletter -T HTML *.html
The name of the WAIS database is computing-service-newsletter This long name is used since a single directory is used for all WAIS databases - it will save confusion if other departments wish to index their own departmental newsletters.
The WAIS database can be accessed by a dedicated WAIS client or by a WWW browser which contains support for the WAIS protocol. The WAIS database can be accessed by giving the URL wais://www.leeds.ac.uk/computing-service-newsletter
wais.pl is a CGI script which is distributed with the NCSA httpd server.
Son of wais.pl is a CGI script which is based on the wais.pl script.
SFGate is a CGI script which interfaces to WAIS servers. SFGate provides a forms interface which can be used to access a number of WAIS databases. It is available at the URL http://ls6-www.informatik.uni-dortmund.de/SFgate/SFgate.html A demonstration is available at the URL http://ls6-www.informatik.uni-dortmund.de/SFgate/multiple.html
wwwwais is a small ANSI C program that acts as gateway between waisq or waissearch (programs that search WAIS indexes) and a forms-capable World-Wide Web browser. With the freely distributable freeWAIS package, this program, and your local Web site, you can:
You can FTP the source and related files from the URL ftp://ftp.eit.com/pub/web.software/wwwwais/
You can see how it looks at the URL http //www.eit.com/cgi-bin/wwwwais
A directory is created for each multimedia object. The directory contains the multimedia object itself (e.g. a graphical file, video clip or sound file) together with a keyword file which describes the object. The keyword files are indexed using WAIS. A WWW browser which supports forms is used to run a CGI script. The CGI script invokes the waisq command to search the WAIS database. The output from waisq is then used to create a HTML file which contains a pointer to a thumbnail image of matching multimedia objects.
Figure 6-2 Multimedia Archive.
freeWAIS-sf is an implementation of WAIS developed at Dortmund University. It is available at the URL ftp://ls6-www.informatik.uni-dortmund.de/pub/wais/freeWAIS-0.2-sf-beta.tar.gz
A mailing list has been established to discuss Isite. To join, send an -mail message to listserv@vinca.cnidr.org with the body of the message as subscribe ISITE-L your name To post messages to the list, send to isite-l@vinca.cnidr.org.
Further information is available at the URL http://vinca.cnidr.org/software/Isite/Isite.html
A WAIS overview is available at the URL http://info.cern.ch/hypertext/Products/wais/sources/Overview.html
A list of resources about the Z39.50 information discovery protocol is available at the URL http://ds.internic.net/z3950/z3950.html
This section gives an example of how to install and run a server for the Microsoft Windows environment. The section then goes on to illustrate a number of server management issues which are based on the CERN server for the Unix platform.
Connect to the NCSA server software from the anonymous FTP server at ftp.ncsa.uiuc.edu Then change directory to /Web/httpd/Uni/ncsa_httpd/contrib/winhttpd Finally retrieve the file whtp13p1.zip An example of how to do this using the FTP software is illustrated below.
ftp src.doc.ic.ac.uk
image
cd /Web/ncsa/httpd/Windows/winhttpd
get whtpp13p1.zip
Create a directory called C:\HTTPD on the C: drive of your PC and then move to the directory using the CD \HTTPD command. Then uncompress the file by giving the command:
PKZUNIP -D WHTPP13P1.ZIP
The -D option will preserve the directory structure from the compressed file.
Run Microsoft Windows and create a program icon using the New option on the File menu. The icon should point to the file C:\HTTPD\HTTPD.EXE
Set the time zone in the AUTOEXEC.BAT file so that TZ=GMT.
Run the server program. The window shown below should be displayed.
Figure 7-1 Running The Windows HTTPD Server.
Run a World-Wide Web browser and then enter a URL containing the IP address of your PC. For example if your PC has an IP address of 192.11.1.1 you should enter the address:
http://192.11.1.1/
The following diagram illustrates NCSA Mosaic for X accessing a server running on a PC.
Figure 7-2 Accessing The MS Windows HTTPD Server.
This example is meant to illustrate the installation of a WWW server. In practice the server software is likely to run on a more robust system than a PC running MS DOS, such as a Unix or Windows NT system.
map / file:/apps/WWW/homepage.html
map /* file:/apps/WWW/*
pass file:/apps/WWW/*
fail *
Figure 7-3 A Simple httpd.conf Configuration File
Figure 7-3 shows a simple configuration file for the CERN httpd server. Line 2 specifies that files located under the directory /apps/WWW should be available to the WWW server software. Line 1 specifies that file /apps/WWW/homepage.html is the default file to be displayed when the WWW server is accessed.
protection prot-proxy { # Part 1
serverid www.leeds.ac.uk
mask @(129.11.*.*)
}
protect http:* prot-proxy # Part 2
protect gopher:* prot-proxy
protect ftp:* prot-proxy
protect wais:* prot-proxy
pass http:* # Part 3
pass gopher:*
pass ftp:*
pass wais:*
Exec /cgi-bin/ucs/* /apps/WWW/cgi-bin/ucs/* # Part 4
Exec /cgi-bin/bionet/* /apps/WWW/cgi-bin/bionet/*
Exec /cgi-bin/bmb/* /apps/WWW/cgi-bin/bmb/*
map / file:/apps/WWW/homepage.html # Part 5
map /* file:/apps/WWW/*
pass file:/apps/WWW/*
fail *
AccessLog /var/adm/httpd.log # Part 6
LogFormat Common
LogTime LocalTime
Caching On # Part 7
CacheRoot /usr/info/WWW_cache
CacheSize 300
CacheAccessLog /var/adm/httpd_cache.log
# Delete files from cache after specified number of days
CacheClean http:* 10 Days
CacheClean gopher:* 10 Days
CacheClean wais:* 10 Days
CacheClean ftp:* 10 Days
# Don't cache local files # Part 8
NoCaching http://*.leeds.ac.uk/*
# If a file hasn't been accessed within the last specified
# number of days delete from cache
CacheUnused * 5 days
CacheUnused http://info.cern.ch/* 10 days
CacheUnused http://www.ncsa.uiuc.edu/* 10 days
# ensure dynamically changing documents are only kept for short
# periods e.g. one modified 10 days ago will only last 2 days
CacheLastModifiedFactor 0.2
# If a file was retrieved more than 5 days ago do a
# 'conditional get' request to the source server to check
# that it hasn't been updated in the meantime.
CacheRefreshInterval http://* 5 days
CacheRefreshInterval gopher://* 5 days
CacheRefreshInterval ftp://* 5 days
# CacheDefaultExpiry ensures that Gopher and FTP files are
# cached. The default is 0 which is what we want for http
# documents with neither an expiry nor a last-modified stamp.
CacheDefaultExpiry ftp://* 5 days
CacheDefaultExpiry gopher://* 5 days
# Remove unwanted cached files daily at 3 am (garbage collection).
Gc On
GcDailyGc 3:00
Figure 7-4 A httpd.conf Configuration File
Figure 7-4 shows another configuration file (this is for illustrative purposes - some options may have been superceeded). The various features are summarised below:
Parts 1 and 2 provides a mechanism for ensuring that the proxy gateway cannot be accessed from outside the local domain. Without these options it would be possible for a browser on an external system to use the proxy gateway to gain access to files which are restricted to local use.
Part 3 passes requests for the httpd, gopher, wais and ftp protocols.
Part 4 specifies the location for CGI files.
Part 5 specifies the area of the filestore which can be accessed by the server.
Part 6 describes the location and format of the server log file.
Part 7 specifies that server caching is to be available, and gives the location of the cache and the cache log files, together with the size (in Mbytes) of the cache.
Part 8 specifies the purging frequency for files in the cache.
An example of a typical httpd.log file is shown below.
abc.cs.xyz.edu - - [21/Nov/1994:21:58:58 +0000] "GET /music.html HTTP/1.0" 200
4375<>
gps0 - - [21/Nov/1994:21:59:48 +0000] "GET / HTTP/1.0" 200 2782
abc_pc99.leeds.ac.uk - - [21/Nov/1994:21:59:47 +0000] "GET
http://www.leeds.ac.uk/ HTTP/1.0" 200 2782
abc.nt.com - - [21/Nov/1994:22:00:03 +0000] "GET
/music/NetInfo/MusicFTP/ftp_sites.html HTTP/1.0" 200 13175
Figure 7-5 Example of a httpd.log File.
Note that the names of the machines accessing files from the server have been altered in the diagram. This has been done because it could be argued that such information should be confidential.
A number of servers also support caching by the server. This is illustrated in Figure 7-6.
Figure 7-6 Caching By The Server.
Caching can improve the performance of a WWW service by ensuring that frequently requested files will tend to be stored in the local cache. There is, of course, a danger that if the file on the remote server is updated that an out-of-date file will be retrieved from the cache. In practice, however, httpd server software which supports caching can deal with this issue by, for example, looking at the date of the file on the remote server and, if the remote file is newer than the file in the cache, replacing the file in the cache with the new version of the file.
[Proxy Information]
http_proxy: www.leeds.ac.uk
gopher_proxy: www.leeds.ac.uk
wais_proxy: www.leeds.ac.uk
Figure 7-7 Client Configuration File To Support Caching.
It order for a client to make use of a cache on a server, the client configuration file (e.g. the MOSAIC.INI file) must be suitably configured. Figure 7-7 illustrates the relevant options for the MOSAIC.INI file.
Accesses of the cache are recorded in the cache log file. A typical log file is illustrated in Figure 7-8.
xyz_pc77.leeds.ac.uk - - [21/Nov/1994:00:43:35 +0000] "GET
http://white.nosc.mil/gif_images/NM_Sunrise_s.gif HTTP/1.0" 200 18673
xyz_pc77.leeds.ac.uk - - [21/Nov/1994:00:43:38 +0000] "GET
http://white.nosc.mil/gif_images/glacier_s.gif HTTP/1.0" 200 6474
xyz_pc77.leeds.ac.uk - - [21/Nov/1994:00:43:40 +0000] "GET
http://white.nosc.mil/gif_images/rainier_s.gif HTTP/1.0" 200 18749
Figure 7-8 The httpd_cache Log File.
Note that the names of the machines accessing files from the cache have been altered in the diagram. This has been done because it could be argued that such information should be confidential.
An institution will need to decide whether to use a caching service and, if so, whether to have caching services running on a number of departmental system, to have an institutional caching service, or to use the national caching service at HENSA. In the future it may be possible to chain caches. The possibility in the long term of having institutional, metropolitan, national and continental caches should be considered.
In practice there is a technique known as proxy gateways which can be used to provide access to services off-campus, without compromising local security. With a proxy gateway a trusted system (typically a Unix system which is more secure to hacking than a desktop machine) will have Internet access. Machines in open access cluster can point to the proxy gateway, which will then retrieve information from off-campus services.
It should be noted that with increasing usage of Internet services such as the World-Wide Web, the author believes that the provision of security mechanisms, such as proxy gateways, will be increasingly important.
map /* file:/apps/WWW/*
pass file:/apps/WWW/*
fail *
Figure 7-9 Server Configuration File.
then clients will only be able to access files held under the directory /apps/WWW/.
Note This statement refers to clients running on remote machines. If the client is running on the same machine as the server, the client will normally be able to access files on the server to which it has read access.
Additional levels of security can also be specified:
Servers have been developed for the Windows NT environment. This may provide a robust operating system environment which can be used for providing a WWW server on an Intel platform.
Information about HTTP/NG is available at the URL http://info.cern.ch/hypertext/WWW/Protocols/HTTP-NG/http-ng-status.html
The HTTP/1.0 specification has been submitted as an Internet-Draft and is available for comment at the following URLs: http://www.ics.uci.edu/pub/ietf/http/draft-fielding-http-spec-00.txt and ftp://www.ics.uci.edu/pub/ietf/http/draft-fielding-http-spec-00.txt
The document Setting up a World-Wide Web Server, which is available at the URL http://scholar.lib.vt.edu/reports/Servers-web.html , gives advice on setting up a server.
A collection of utilities intended especially for WWW system administrators is available at the URL ftp://src.brunel.ac.uk/WWW/managers/
A list of server software is available at the URL http://www.cern.ch/hypertext/WWW/Daemon/Overview.html
A list of server software is available at the URL http://www.charm.net/~web/Vlib/Providers/Servers.html
A list of server software is available at the URL http://akebono.stanford.edu/yahoo/Computers/World_Wide_Web/HTTP_Servers/
A hypermail archive of the HTTP-WG mailing list is available at the URL http://www.ics.uci.edu/pub/ietf/http/hypermail/
When a client receives a file from a server it checks on the file type. If the file type indicates that it is an HTML document, the file will be displayed by the browser. Otherwise the browser's configuration file can specify an external viewer which can be used to display the file. A list of widely used external viewers is given in Table 8-1.
File Format Viewer
JPEG LVIEW (MS Windows) xv (X Windows)
Postscript Ghostview
DVI xdvi (X Windows)
MPEG mpeg_play (X Windows and MS
Windows)
Table 8-1 Popular Viewers.The association between the file type and the viewer is given in the browser's configuration file. A typical configuration file for Mosaic for Windows is given in Figure 8-1.
[Viewers]
TYPE0="audio/wav"
TYPE1="application/postscript"
TYPE2="image/gif"
TYPE3="image/jpeg"
TYPE4="video/mpeg"
TYPE5="video/quicktime"
TYPE6="video/msvideo"
TYPE7="application/x-rtf"
TYPE8="audio/x-midi"
TYPE9="audio/basic"
TYPE10="image/x-action"
TYPE11="application/x-w3launch"
application/postscript="L:\winapps\ghost\gsview %ls"
application/x-w3launch="n:\windept\bmb\w3launch\w3launch %ls"
image/gif="L:\winapps\mosaic2\lview %ls"
image/x-action="n:\windept\bmb\action25\playact %ls"
image/jpeg="L:\winapps\mosaic2\lview %ls"
video/mpeg=""
video/quicktime=""
video/msvideo=""
audio/wav=""
audio/x-midi="mplayer %ls"
application/x-rtf="write %ls"
Figure 8-1 Part of a MOSAIC.INI File.
As a general principle there are dangers in automatically invoking applications from WWW clients.
Further details on the W3Launch program is available at the URL http://www.leeds.ac.uk/bionet/student/pre-stud.htm
Figure 8-2 W3Launch.
It should be noted that W3Launch is an application developed at the Unievsrity of Leeds - it is not part of WWW itself.
#!/bin/sh
echo Content-type: text/html
echo
if [ $# = 0 ]
then
echo "<HEAD>"
echo "<!-- Script written by Brian Kelly --!>"
echo "<TITLE>Search University Phone Directory</TITLE>"
echo "<ISINDEX>"
echo "</HEAD>"
echo "<BODY>"
echo "<H1>Phone Directory</H1>"
echo "Enter surname of the person you are searching for.<P>"
echo "Script written by <A HREF=http://www.leeds.ac.uk/
ucs/people/BKelly/bk.html>Brian Kelly</A>."
echo "</BODY>"
else
echo "<HEAD>"
echo "<TITLE>Results Of Search</TITLE>"
echo "</HEAD>"
echo "<BODY>"
echo "<H1>Results of Search for $* </H1>"
echo "<PRE><TT>"
grep -i "$*" /apps/data/Telephone_Directory
echo "</PRE></TT>"
echo "</BODY>"
fi
Figure 8-3 Script To Generate An HTML Document.
The program, which is a C shell script which runs on the Unix server system, can be executed by selecting the URL http://www.leeds.ac.uk/ucs/cgi-bin/phone
When the URL is selected since no arguments are provided, the first part of the if statement is run. This will generate the following HTML document:
<HEAD>
<!-- Script written by Brian Kelly --!>
<TITLE>Search University Phone Directory</TITLE>
<ISINDEX>
</HEAD>
<BODY>
<H1>Phone Directory</H1>
Enter surname of the person you are searching for.<P>
Script written by <A HREF=http://www.leeds.ac.uk/
ucs/people/BKelly/bk.html>Brian Kelly</A>.
</BODY>
Figure 8-4 Virtual HTML Document.
The <ISINDEX> tag generates a search dialogue box. The HTML document is rendered as shown below.
Figure 8-5 Running The Script.
When text is entered in the Search box and the <Enter> key pressed, the script in Figure 8.4 is executed again. This time, since the program will be given an argument, the second part of the if statement will be executed. This will generate the HTML tags and then invoke the Unix grep command to search a file for lines containing the search string.
Figure 8-6 Output From The Script.
Examples of the use of CGI programs are available at the URl http://hoohoo.ncsa.uiuc.edu/cgi/examples.html
A tutorial on CGI is available at the URL http://www.charm.net/~web/Tutorial/CGI/
A CGI Programmer's Reference is available at the URL http://www.halcyon.com/hedlund/cgi-faq/
An archive of useful CGI programs is available at the URL ftp://ftp.ncsa.uiuc.edu/Web/httpd/Unix/ncsa_httpd/cgi/
A form is defined by the <FORM ...> and </FORM> HTML tags. The <FORM> tag has the syntax:
<FORM METHOD="method" ACTION="url">
For example:
<FORM METHOD="post" ACTION="http://leeds.ac.uk/ucs/cgi-bin/myscript">
will send the input data to be processed by myscript.
An example of a form is shown below:
<TITLE>Fill-Out Form Example #7</TITLE>
<H1>Fill-Out Form Example #7</H1>
This is another fill-out form example, with toggle buttons. <P>
<HR>
<FORM METHOD="POST"
ACTION="http://hoohoo.ncsa.uiuc.edu/htbin-post/post-query">
<H2>Godzilla's Pizza -- Internet Delivery Service, Part II</H2>
Type in your street address: <INPUT NAME="address"> <P>
Type in your phone number: <INPUT NAME="phone"> <P>
Which toppings would you like? <P>
<OL>
<LI> <INPUT TYPE="checkbox" NAME="topping" VALUE="pepperoni">
Pepperoni.
<LI> <INPUT TYPE="checkbox" NAME="topping" VALUE="sausage">
Sausage.
<LI> <INPUT TYPE="checkbox" NAME="topping" VALUE="anchovies">
Anchovies.
</OL>
How would you like to pay? Choose any one of the following: <P>
<OL>
<LI> <INPUT TYPE="radio" NAME="paymethod" VALUE="cash" CHECKED>
Cash.
<LI> <INPUT TYPE="radio" NAME="paymethod" VALUE="check"> Check.
<LI> <I>Credit card:</I>
<UL>
<LI> <INPUT TYPE="radio" NAME="paymethod" VALUE="mastercard">
Mastercard.
<LI> <INPUT TYPE="radio" NAME="paymethod" VALUE="visa"> Visa.
<LI> <INPUT TYPE="radio" NAME="paymethod"
VALUE="americanexpress">
American Express.
</UL>
</OL>
Would you like the driver to call before leaving the store? <P>
<DL>
<DD> <INPUT TYPE="radio" NAME="callfirst" VALUE="yes" CHECKED>
<I>Yes.</I>
<DD> <INPUT TYPE="radio" NAME="callfirst" VALUE="no">
<I>No.</I>
</DL>
To order your pizza, press this button: <INPUT TYPE="submit"
VALUE="Order Pizza">. <P>
</FORM>
Figure 8-7 HTML Document Defining A Form.
This example is available at the URL http://www.ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/example-7.html
The way in which form is displayed is illustrated below.
Figure 8-8 Using A Form.
A forms testing suite is available at the URL http://www.research.digital.com/nsl/formtest/home.html
w3new is a program which will extract a list of URLs from the Mosaic client hotlist file or extract URLs from a HTML document. It will then retrieve the modification dates for each document listed and output a HTML file with the URLs sorted by their last modification date.
Information about the program is available at the URL http://www.stuff.com/~bcutter/home/programs/w3new/w3new.html The utility was written by Brooks Cutter (mailto:bcutter@stuff.com).
wusage is a WWW server usage meter which produces weekly activity reports in HTML. In addition it provides graphical displays of server usage.
Further information is available at the URL http://siva.cshl.org/wusage.html The software is available from the URL ftp://isis.cshl.org/pub/wusage wusage was written by Thomas Boutell (mailto:boutell@netcom.com).
getstats (formerly called getsites) is a versatile WWW server log analyser. It is available at the URL http://www.eit.com/software/getstats/getstats.html
weblint is a Unix utility for checking the syntax of HTML documents. The checks include illegally nested, overlapped, unclosed and obsolete tags. Further details are available at the URL http://www.khoros.unm.edu/staff/neilb/weblint.html The software can be obtained from the URL ftp://ftp.khoros.unm.edu/pub/perl/www/. The utility was written by Neil Bowers, Khoral Research Inc. (mailto:neilb@khoros.unm.edu) The email list weblint@khoros.unm.edu provides announcements of new versions of Weblint. Email Neil Bowers if you wish to be added to the list.
Verify_links is a robot which performs link verification. Further information is available at the URL http://wsk.eit.com/wsk/dist/doc/admin/webtest/verify_links.html
MOMspider (Multi-Owner Maintenance spider) is a tool which can be used to help information providers and system managers to maintain links to documents. MOMspider is available at the URL http://www.ics.uci.edu/WebSoft/MOMspider/
Hypermail is a program that converts a file of email messages to a hypertext WWW form. It is available at the URL http://gummo.stanford.edu/html/hypermail/hypermail.html
The following utilities are available at the URL ftp://src.doc.ic.ac.uk/pub/packages/infosystems/WWW/tools
checkweb looks for dead links in your Web
html+tables.shar creates preformatted text tables from HTML+ Table definitions
mosaic-wais-cli.pl does a WAIS search using Mosaic from the command line
newslist/ compiles an HTML page of links to all newsgroup on your server
simon/ URL database to replace NCSA Mosaic's Hotlist
test-cgi/ sets up HTTP environment for a CGI script
url-get.pl a perl script which brings in any document given its URL
w3get.pl retrieves a HTML page named by a URL and all HREFs and IMGs in it
The author does not know the answer to these questions. Fortunately WWW is attracting the interests of lawyers, philosophers and artists who are starting to address these issues. Many of the papers which have been published address issues which affects WWW providers in the USA. The American Constitution, and in particular the amendment on free speech, means that much of the work published in the USA in this area is not relevant to the UK.
A future edition of this handbook may contain information relevant to UK legislation and culture. This edition covers a number of issues are raised which WWW service and information providers should consider.
However even the most liberal individual is likely to be offended by some of the pornography which is believed to be available on the Internet. In addition UK legislation on computer pornography is likely to be introduced shortly. This could mean that universities have a legal obligation to concern itself with computer pornography.
A WWW manager may have the responsibility to ensure that copyright materiel is not made available unless the copyright holder has granted permission. This may affect research papers which have been submitted for publication. It may also affect the use of photographs, drawings and maps, for which the copyright may be owned, for example, by the photographer or the organisation which commissioned the photograph.
Figure 10-1 The "What's New On Mosaic" Page.
JANET may be used for any legal activity in furtherance of the aims and policies of a connected organisation, subject to a number of rules. For example, the following uses are not permitted on JANET:
Cranfield University have published guidelines for information providers which is available at the URL http://www.cranfield.ac.uk/docs/publish_code.html
Information about the Data Protection Act is available at the URL http://www.open.gov.uk/dpr/dprhome.htm
Figure 11-1 CWIS At HCC.
The HCC CWIS was developed to support its goal of becoming the "Technological Training Centre of the Pacific". The most important aspects of developing and managing an effective CWIS are managerial and not technical. Formulating the objectives of a CWIS, resourcing it and developing a training programme are key issues which an institutional needs to address.
The Universities and Colleges Teaching, Learning and Information Group (UCTLIG) are producing a CWIS Manager's Handbook which will address many of these issues.
Polly-Alida Farrington's listing of CWISes is available at the URL http://www.rpi.edu/Internet/cwis.html
Lists of (global) CWISes are available at the URLs http://www.rpi.edu/Internet/cwis.html and http://kawika.hcc.hawaii.edu/ws94/cwis.html
The CWIS-L Listserv mailing list provides a forum for the discussion of topics related to campus-wide information systems. To subscribe send the message SUB CWIS-L your name to the address LISTSERV@MSU.EDU
A Framework for Administering NASA's Web Information Hypermedia is available at the URL http://naic.nasa./gov/www-framework.html
Figure 12-1 Early Example Of A Distributed Multimedia Teaching
Application.
A more sophisticated teaching application was developed by the School of Chemistry in conjunction with Imperial College. The example illustrated in Figure 12-2 makes use of a chemistry MIME type.
![](fig12-2.gif")
Figure 12-2 Using a MIME Chemistry Type.
In this example the WWW client is configured to associate the MIME type with the RasMol program. For example in NCSA Mosaic For X the line:
chemical/x-pdb; rasmol %s
is included in the .mailcap file. When a URL with the extension .pdb is selected the file will be downloaded and the Rasmol program launched, as illustrated in Figure 12-2.
Further information on this project is available at the URL http://chem.leeds.ac.uk/Project/MIME.html
The Globewide Network Academy (GNA) is a consortium of educational and research organisations. Its mission is to provide a central organisation in which students, teachers, scholars and researchers can meet and interact. Further information about GNA is available at the URL http://uu-gna.mit.edu:8001/uu-gna/
Mark Cox, Department of Industrial Technology, University of Bradford presented a paper at the Mosaic and the Web conference on Robotic Telescopes: An Interactive Exhibit on the Web. This paper is available at the URL http://www.eia.brad.ac.uk/mark/wwwf94/wwwf94.html
Mark also has a collection of pointers to hardware control services over the Web which is available at the URL http://www.eia.brad.ac.uk/mark/fave-inter.html
A Virtual Frog Dissection Kit has been developed at the LBL. It is available at the URL http://george.lbl.gov/ITG.hm.pg.docs/Whole.Frog/Whole.Frog.html
Figure 12-3 Frog Dissection.
CTISS is available at the URL http://www.ox.ac.uk/cti/
CTI Centre For Biology is available at the URL http://www.liv.ac.uk/ctibiol.html
CTI Centre For Chemistry is available at the URL http://www.liv.ac.uk/ctichem.html
CTI Centre For Law is available at the URL http://crocus.csv.warwick.ac.uk/WWW/law/default.html
CTI Centre For Psychology is available at the URL http://ctipsych.york.ac.uk/
CTI Centre For Sociology is available at the URL http://lorne.stir.ac.uk/departments/cti_centre/
CTI Centre For Textual Studies is available at the URL http://www.ox.ac.uk/depts/humanities/
BioNet Project is available at the URL http://www.leeds.ac.uk/bionet.html
CLIVE Project is available at the URL http://www.vet.ed.ac.uk/
Insurrect Project is available at the URL http://av.avc.ucl.ac.uk/
Institute Of Computer Based Learning, Heriot-Watt is available at the URL http://www.icbl.hw.ac.uk/
INTERACT Project is available at the URL http://medusa.eng.cam.ac.uk/~interact/
Interactive Learning Centre, University of Southampton is available at the URL http://ilc.ecs.soton.ac.uk/welcome.html
ITTI is available at the URL http://www.hull.ac.uk/Hull/ITTI/homepage.html
PsyCLE Project is available at the URL http://ctipsych.york.ac.uk/Psycle/PsyCLEinfo.html
STILE Project is available at the URL http://indigo.stile.le.ac.uk/
TLTP is available at the URL http://www.hcbl.hw.ac.uk/tltp/
TLTP Archaeology Consorteum is available at the URL http://www.brad.ac.uk/acad/archsci/homepage.html
TLTP Mathematical Project is available at the URL http://othello.ma.ic.ac.uk/
Pointers to global uses of WWW for teaching is available at the URL http://wwwhost.cc.utexas.edu/world/instruction/index.html
Harry Kriz's paper "Teaching and Publishing in the World Wide Web" is available at the URL http://learning.lib.vt.edu/webserv/webserv.html
Figure 13-1 WIT.
Figure 13-2 Posting To Usenet News.
Figure 13-3 A Hypermail Archive.
Figure 13-4 The Mailserv Interface To Mailing List Servers.
Figure 13-5 Accessing A Video On WWW.
One interesting application of a multimedia desktop conferencing systems is MONET (Meeting on the Network) which is described in Applications of Mosaic in Health Care Delivery by Srivasa et al. This paper, which was presented at the Mosaic and The Web conference, is available at the URL http://www.ncsa.uiuc.edu/SDG/IT94/Proceedings/MedTrack/srivasa/artemis.html
Figure 13-6 MONET.
At the time of writing many of these services are experimental. However, given the rapid growth of WWW and the extent of development work which is going on, such services may be mainstream in the near future.
About 200 of the papers which were given at the second WWW conference, Mosaic and The Web, were available on WWW before the conference began. Perhaps one important question which the academic community should be addressing is whether it should be the standard practice for conference proceedings to be made available on WWW.
Examples of conference proceedings available on WWW is given in Appendix 5.
Figure 14-1 Gateway To A Library Catalogue.
In Figure 14-1 a form is completed. The term Internet is used as a search term. Once the form is submitted the data is sent to a CGI program. In this case the CGI program is a C program which invokes the BRS free text retrieval system. The output from the BRS program is then processed to generate the appropriate HTML markup. The output from the search is illustrated in Figure 14-2.
Figure 14-2 Output From The Library Catalogue.
SALSER is an online information service about serials held in Scottish academic and research libraries. It can be accessed at the URL http://salser.ed.ac.uk/
The Clearinghouse for subject-oriented Internet resource guides is available at the URL http://http2.sils.umich.edu/~lou/chhome.html
The EINet Galaxy collection of online resources is available at http://galaxy.einet.net/galaxy.html
The CERN Virtual Library is available at the URL http://info.cern.ch/hypertext/DataSources/bySubject/Overview.html
The Boulder Community Network service is available at the URL http://bcn.boulder.co.us/ Its policy statement is available at the URL http://bcn.boulder.co.us/bcn/policy.html The policy statement includes a bill of rights, a freedom to read statement and a freedom to view statment.
The following Library resources may also prove useful:
Eric Morgan's article on Libraries and the Web in Public Access Computer Systems Review, 5(6) 1994:5-26 is available at the URL http://www.lib.ncsu.edu/staff/morgan/www-and-libraries.html
Uniform Resource Characteristics (URCs) will provide meta-information about a document. This information could include information about the author, keywords, expiry dates (for caching servers), copyright and cost information. URCs could also provide information about the quality of the document. For example a seal of approval (SOAP) could be given by university publications group which confirms, by the use of a digital signature, that the document is a PhD thesis.
Uniform Resource Identifiers (URIs) includes URLs, URIs and URCs. The URI specification is available as RFC 1630. The mailing list uri@bunyip.com is used to discuss URIs. Send email to uri-request@bunyip.com to subscribe to this list. Archives of the list are available at the URL http://www.acl.lanl.gov/URI/archive/uri-archive.index.html
Please note that before sending a message to any of these lists please listen to the discussions first and, where possible, read the information about the list. You should not send simple questions about, say, installing Mosaic on your home PC to a list for developers of the WWW protocols.
For example if John Smith wanted to subscribe to the www-announce list he would send the message subscribe www-announce John Smith
An overview of CERN mailing lists is available at the URL http://info.cern.ch/hypertext/WWW/Administration/Mailing/Overview.html Alternatively send an email message to listserv@info.cern.ch containing line lists to receive a list of lists or review list to receive a list of subscribers to list.
This list is archived at the URL http://198.92.133.3/menus/6581.htm and at the URL http://gummo.stanford.edu/html/hypermail/hypermail.html
This list is archived. A threaded version of the archive is available at the URL http://gummo.stanford.edu/html/hypermail/archives.html
A mailing list has been established for technical discussion about libwww-perl, including problem reports, interim fixes, suggestions for features, and contributions. The mailing list address is libwww-perl@ics.uci.edu and administrivia (including subscribe requests) should be sent to libwww-perl-request@ics.uci.edu
A Hypermail archive of the mailing list is also available at the URL http://www.ics.uci.edu/WebSoft/libwww-perl/archive/
NOTE This list is now believed to be defunct since it was being used for basic Mosaic questions, rather than providing a forum for Mosaic developers.
Further information is available at the URL http://www.uth.tmc.edu/mac_info/machttp/mailing_list.html
An archive is available at the URL http://naic.nasa.gov/naic/archives
The UNITE archives are available at the URL http://mailbase.ac.uk/pub/lists/unite
The archives are available at the URL http://mailbase.ac.uk/pub/lists/web-support
To get help on the mailserver commands put HELP in your message body To receive a list of the available mailing list put LISTS in the body To receive a list of subscribers in a list put SEND/LIST webserver-nt in the body.
The archives are held at the URL http://www.research.att.com/www-buyinfo/about.html
An archive of the list is held at the URL http://www.eit.com/mailinglists/www-courseware/archive/
An archive of the list is held at the URL http://www.eit.com/mailinglists/www-literature/archive/
To subscribe send mail to www-security-request@nsmx.rutgers.edu containing the message subscribe www-security
An archive of the list is held at the URL http://www.verity.com/www-security.html
Information about the www-security list is also available at the URL http://www-ns.rutgers.edu/www-security/index.html
To subscribe to the Virtual Reality Markup Language (VRML) list send mail to majordomo@wired.com containing the message subscribe www-vrml
Further information is available at the URL http://www.wired.com/vrml/
Yahoo is available at the URL http://akebono.stanford.edu/yahoo/Computers/
Computers: World-Wide Web is available at the URL http://akebono.stanford.edu/yahoo/Computers/World_Wide_Web/
One World is available at the URL http://oneworld.wa.com/htmldev/devpage/dev-page1.html
Web Weaver's Page is available at the URL http://www.nas.nasa.gov/RNR/Education/weavers.html
WebStars: Astrophysics in Cyberspace is available at the URL http://guinan.gsf.nasa.gov/
Pointer's to WWW resources (Toronto University) is available at the URL http://www.utirc.utoronto.ca/
PC Week's pointers to WWW resources is available at the URL http://www.upcweek.ziff.com/~pcweek/pointers.html
Oslonett is available at the URL http://www.oslonet.no/html/demo/WWWinfo/html
CGI Programmer's Reference is available at the URL http://www.halcyon.com/hedlund/cgi-faq/
The WWW Locator Guide is available at the URL http://groucho.gsfc.nasa.gov/Code_520/locator/locator.html
A list of World Wide Web FAQs and Guides is available at the URL http://cuiwww.unige.ch/OSG/FAQ/www.html
ftp://ftp.cica.indiana.edu/pub/win3/icons
http://white.nosc.mil/images.html
http://guinan.gsfc.nasa.gov/Alan/Richmond.html
http://www.cli.di.unipi.it/iconbrowser/icons.html
http://www.jsc.nasa.gov/~mccoy/Icons.index.html
http://www.cs.yale.edu/HTML/YALE/CS/HyPlans/loosemore-sandra/clipart.ht/Altml
Further information about the second WWW conference Mosaic and The Web, held at Chicago on 17-20 October 1994 is available at the URL http://www.ncsa.uiuc.edu/SDG/IT94/Proceedings/ A searchable index of the papers is available at the URL http://www.verity.com/spidersearch.html
The third WWW conference will be held at Darmstadt, Germany on 10-14 April 1995. Further details are available at the URL http://www.igd.fhg.de/www/www95/www95.html
The Mailbase mailing list service run a WWW server which is available at the URL http://www.mailbase.ac.uk/
The Micros Hensa service run a WWW server which is available at the URL http://micros.hensa.ac.uk/
The Unix Hensa service run a WWW server which is available at the URL http://unix.hensa.ac.uk/
CTISS run a WWW server which is available at the URL http://www.ox.ac.uk/cti/
The Office for Library and Information Networking (UKOLN) runs a WWW server which is available at the URL http://ukoln.bath.ac.uk/UKOLN/home.html
NISS is setting up a WWW server which is available at the URL http://www.niss.ac.uk/
A TLTP specific Web Server is available at the URL http://www.icbl.hw.ac.uk/tltp
The Social Sciences Information Gateway is available at the URL http://sosig.esrc.bris.ac.uk/
CCTA, the UK Government computer agency, runs a WWW server which is available at the URL http://www.open.gov.uk/
A UK sensitive map is available at the URL http://scitsc.wlv.ac.uk/ukinfo/uk.map.html This service is maintained by the School of Computing and Information Technology, University of Wolverhampton (email jphb@scitsc.wlv.ac.uk)
ChemConf'93 is available at the URL gopher://info.umd.edu:901/11/inforM/Educational_Resources/Faculty_Resources_and_Support/ChemConference
NASA High Alpha Conference IV (high angle of attack) is available at the URL http://www.dfrf.nasa.gov/Workshop/HighAlphaIV/highalpha.html
The HIDEC Electronic Conference (the F-15 Highly Integrated Digital Electronic Control program) is available at the URL http://mosaic.dfrf.nasa.gov/Workshop/HIDEC/Conf.DIRS/.htmllinks/ConfWeb.html
DL94:Proceedings of the First Annual Conference on the Theory and Practice of Digital Libraries is available at the URL http://atg1.wustl.edu/DL94
On-Line Proceedings of ACL-94 (Association of Computational Linguistics) is available at the URL http://xxx.lanl.gov/cmp-lg/ACL-94-proceedings.html
...and its post-conference workshops is available at the URL http://xxx.lanl.gov/cmp-lg/ACL-94-post.html
1st Electronic Conference in Computational Chemistry (ECCC) is available at the URL http://hackberry.chem.niu.edu:70/0/ECCCinformation.html
And as a wonderful example of self-referencing, a la Douglas Hofstadter's Godel, Escher, and Bach, see the URL http://www.automatrix.com/conferences
An example of an "after-the-fact" online conference is available at the URL http://stardust.jpl.nasa.gov/igarss/
"Mosaic Quick Tour For Windows" by Gareth Branwyn, published by Ventana Press costs [[sterling]]7.95 (ISBN 1-56604-194-5). Further information available at the URL http://www.vmedia.com/vvc
"The Internet via Mosaic and World-Wide Web" by Steve Browne, published by ZD Press costs [[sterling]]22.99 (ISBN 1-56276-259-1).
"The World-Wide Web, Mosaic and More" by Jason J Manger, published by McGraw Hill costs [[sterling]]24.95 (ISBN 0-07-709132-9).
"Teach Yourself HTML Web Publishing in a Week" by Laura Lemay, to be published by Sams' Publishing (ISBN 0-672-30667-0). This book discusses not only the various aspects of HTML, Web servers, gateways, forms, and imagemaps, but also focuses strongly on style and structure and navigation. In other words, its not just a reference, its also a style guide.
"HTML For Fun and Profit" by Mary Morris, to be published by Prentice-Hall. It includes forms, clickable images, server includes, indexing, linking and basic formatting. It will have a CD-ROM with examples and tools on it. See the URL http://www.sun.com/smi/ssoftpress/
"The Mosaic Handbook for the X Window System" by Richmond Koman and Paula Feguson, published by O'Reilly (ISBN 1-56592-095-3), "The Mosaic Handbook for Microsoft Windows System" by Richmond Koman, published by O'Reilly (ISBN 1-56592-094-5) and "The Mosaic Handbook for the Macintosh" by Richmond Koman, published by O'Reilly (ISBN 1-56592-096-1). These books, which cost [[sterling]]22 each, contain a CD-ROM (the X Window book) or a floppy disk which contains a copy of the Mosaic software.
.net published by Fortune Publishing Ltd. Further details are available at the URL http://www.futurenet.co.uk/home.html or by sending email to netmag@futurenet.co.uk
infoHighway ISSN 1355-2465. For further details send email to p.deacon@eurodollar.co.uk or david@pipex.net
Wired. Further details are available at the URL http://www.hotwired.com/ For subscriptions details send email to subscriptions@wired.com
3W cost [[sterling]]24 for 6 issues. Further information is available at the URL http://www.3w.com/3W/
The Handbook was converted to HTML format using the RTFtohtml and RTFtoweb conversion programs.
About The Author
Brian Kelly is the Head of User Support, Computing Service, University of Leeds. He first came across the World-Wide Web (WWW) at a workshop on Internet tools organised by the Information Exchange Special Interest Group, University of Leeds on 9th December 1992. In January 1993 the Computing Service installed the CERN httpd server on its central Unix system - this was probably the first WWW service provided by a central service in the UK academic community.
Following an unannounced visit from Robert Cailliau, one of the WWW co-developers from CERN in March 1993, the Computing Service became convinced of the importance of WWW. The Computing Service contribution to the University Open Day, held in May 1993, was centered on the World-Wide Web: for example the Open Day programme was available on WWW.
Brian has given presentations about WWW at the universities of Aberdeen, Bangor, Bradford, Kent, Oxford, Sussex and Manchester Metropolitan University. He gave a poster presentation at the first WWW '94 conference in Geneva and gave a paper on Becoming An Information Provider on the World-Wide Web at the INET 94 / JENC 5 conference in Prague in June 1994. He ran a WWW Tutorial at the Network Service Conference in London in November 1994.
Acknowledgments
I would like to thank the following for their assistance and comments on this handbook:
Bruce Altner, Nigel Bruce, John D Lewis, Chris Lilley, Jim Hobbs, Ken Hensarling, Roger Horton, Jon Knight, Inke Kolb, Martijn Koster, Paul Leclerc, Neal McBurnett, Sean Martin, Eric Morgan, George Munroe, Alan Richmond, Paul Sutton, Ton Verschuren, Anne Worden, Bruce Washburn.
The author, of course, accepts responsibility for any errors in this handbook.
Feedback
The author welcomes constructive comments and feedback on this handbook, which should be sent to the email address B.Kelly@leeds.ac.uk Please note, however, that the author is unable to provide individual advice or assistance.
Copyright
Copyright (C) 1994 by Brian Kelly.
All rights reserved. This work may be copied in its entirety, without modification and with this statement attached. Redistribution in part or with modifications is not permitted without advance agreement from the copyright holder.
Copyright of WWW pages shown in this Handbook belongs to the individual or organisation which created the pages. Any copyright holder who wishes for an image to be removed from this Handbook should contact the author of the Handbook.