Guides to Web Catalogs:

http://www.lights.com/webcats/
important gateway,
originally from the University of Saskatchewan, Canada,
originally  http://library.usask.ca/hywebcat
an extension of Hytelnet catalog of Telnet library catalogs.
Offers access to a large number of Web catalogs,
organized by location, vendor etc.
also includes vendor homepages

http://sunsite.berkeley.edu/Libweb
Library servers via WWW:
3,500 pages from 100 countries,
plus a list of other resources for this field

Online catalogs with webbed interfaces:
http://www.lib.ncsu.edu/staff/morgan/alcuin/wwwed-catalogs.html

lib-web-cats: library Web pages, online catalogs ....
over 4,700 libraries worldwide:
http://staffweb.library.vanderbilt.edu/breeding/libwebcats.html

Online Dewey Decimal Classification Catalogs:
http://www.oclc.org/oclc/fp/worldwide/online_ddc_catalogs.htm

Web Catalog features:

All / most web catalogs offer:
Easy to use web interface
Enter search in boxes
Receive picklist of results
Brief / complete details of books
Useful help files

Advanced web catalogs may offer:
Enter different search terms in different boxes, select operators from pop-up list
Use boxes / pop-ups to select language, date etc.
Standard / MARC displays
Send bibliographic data by e-mail / to a local file
Send data as text / html / Procite / MARC communications format
Sort output
Links direct to digitized files / illustrations etc.

Web catalog interfaces can vary:
Attractive / less attractive general appearance
Basically textual interface / Heavy use of icons, buttons and visual signals
Brief and simple / long and complex help files
Simple / complex command language
Clear / complex presentation of numerical results and first picklist
Clear / complex layout and identification of bibliographic data

The interface selected for a specific library web catalog should be appropriate to:
Mission / community served:
Major academic / research libraries will need different interface from
Public library / small college library

http://catalog.loc.gov
Library of Congress catalogs; twelve million records;
implemented Aug. 1999, Endeavor / Voyager software
quality interface: comprehensive search forms, popups;
command line searching for advanced users
still available in Command Keyword searching

http://www.nypl.org
New York Public: world level public library;
easy searching; direct:
http://catnyp.nypl.org);
type term, touch enter;
can limit by material, language, date;
will e-mail results; Innovative Interfaces software

http://dpweb1.dp.utexas.edu/lib/utnetcat
U. Texas, 6 million items; easy to use;
quick search box on first screen.
Follow browse to view catalogs in alphabetical order.
Select keyword to search for specific items;
note well laid out entry form:
enter terms in separate boxes, select operator;
limit to location / format / language /
place of publication / year of publication
(note pop-up boxes for frequently-used choices).
Catalog will even identify books with special bindings:
try poetry and vellum (i.e. system indexes words in notes).
Links direct to some digitized maps:
try Kuwait and maps
(select subject keywords if searching from quick search box);
from picklist click on a long URL ending in .jpg, .gif etc.

http://www.melvyl.ucop.edu
Union Catalog U. California; Melvyl catalog;
select long display for details; includes some periodical articles; sophisticated e-mail:
user can add note, include / exclude diacritics.

http://library.unm.edu/
University of New Mexico Web catalog;
offers MARC format, will export via e-mail or to local disk;
will even download in MARC communication format
direct to local hard disk;
Innovative Interfaces software

http://copac.ac.uk/copac/
COPAC:
(CURL (Consortium of University Research Libraries) OPAC):
Unified web access to major British university libraries

http://www.aladin.wrlc.org
Washington (DC) Research Library Consortium:
Aladin: Access to Library and Database Information Network;
will show MARC format;
OCLC system; uses star system to show relevance

ILLINET Online: Illinois Library Computer Systems Organization:
http://pac.ilcso.uiuc.edu/

http://liba.lboro.ac.uk:8008/www-bin/www_talis
Loughborough University, England; Talis-Web (BLCMP)

http://library.usask.ca
University of Saskatchewan Library,
home of Hywebcat, with good serials control system

Louis: Louisiana Online University Library Catalogs;
standardized Epixtech (formerly Ameritech)
interface to various universities:
http://webpac.louis.lsu.edu:8080/

http://hplus.harvard.edu/
Harvard, eight million records
largely converted from previous telnet-style access
for description / plans see
http://hplus.harvard.edu/holliswebinfo.html#access

http://voyager.aber.ac.uk/
The University of Wales:
well-presented bilingual site
(Endeavor (US) software)

http://www.bl.uk/  British Library:
select Online / OPAC97 for OPAC;
note sponsorship from Amazon.co.uk;
select Online / Gabriel for links to other European libraries, e.g.

Library catalogs sponsored by / linking through to booksellers:
the shape of things to come?

http://www.bnf.fr/ National Library, France
 

Note also Z39.50 gateways to (multiple) resources:

http://lcweb.loc.gov/z3950/gateway.html#other
LC Z39.50 gateway

http://cicvel.lib.uiowa.edu/
Union catalog of Big Ten universities

SILO Locator -- Iowa's Card Catalog (epixtech Horizon):
http://server.silo.lib.ia.us/cgi-bin/z3950/zform.CGI?SILO