Wide area information server

Wide Area Information Servers or WAIS is a client-server text searching system that uses the ANSI Standard Z39.50 Information Retrieval Service Definition and Protocol Specifications for Library Applications" (Z39.50:1988) to search index databases on remote computers. It was developed in the late 1980s as a project of Thinking Machines, Apple Computer, Dow Jones, and KPMG Peat Marwick.

WAIS did not adhere to either the standard or its OSI framework (adopting instead TCP/IP) but created a unique protocol inspired by Z39.50:1988.

The WAIS protocol and servers were primarily promoted by Thinking Machines Corporation of Cambridge, Massachusetts. Thinking Machines produced WAIS servers which ran on their massively parallel CM-2 (connection machine) and SPARC-based CM-5 MP supercomputers. WAIS clients were developed for various operating systems including Windows, Macintosh, NeXT and UNIX. TMC, however, released a free open source version of WAIS to run on Unix in 1991.

Inspired by the WAIS project on full text databases and emerging SGML projects Z39.50 version 2 or Z39.50:1992 was released. Unlike its 1988 predecessor it was a compatible superset of the ISO 10162/10163 work that had been done internationally.

With the advent of Z39.50:1992, the termination of support for the free WAIS from Thinking Machines and the establishment of WAIS Inc as a commercial venture (their WAIS was written to use the Fulcrum fulltext engine), the U.S. National Science Foundation funded CNIDR to create a clearinghouse of information related to Internet search and discovery systems and to promote open source and standards. CNIDR created a new freely available open-source WAIS. This created first the freeWAIS package based on the wais-8-b5 codebase implemented by Thinking Machines Corp and then a wholly new software suite Isite based upon Z39.50:1992 with Isearch as its full text search engine.

Ulrich Pfeifer and Norbert Gövert of the computer science department of the University of Dortmund took the CNIDR freeWAIS code and extended it to become freeWAIS-sf: sf means structured fields and indicated its main improvement. Ulrich Pfeifer rewrote freeWAIS-sf in Perl where it became WAIT.

Inspired also by WAIS, especially its "Directory of Servers", Eliot Christian of USGS envisioned GILS: Government Information Locator Service. GILS (based upon Z39.50:1992 with some WAIS-like extensions) became a U.S. Federal mandate as part of the Paperwork Reduction Act of 1995 (44 U.S.C. § 3511).

Directory of Servers

Thinking Machines Corp provided a service called the Directory of Servers. It was a WAIS server like any other information source but contained information about the other WAIS servers on the Internet. When one would create a WAIS server with the TMC WAIS code it would create a special kind of record containing metadata and some common words to describe the content of the index. It would be uploaded to the central server and indexed along with the records from other public servers. One could search the directory to find servers that might have content relevant to a specific field of interest. This model of searching for (WAIS) servers to search became the role model for GILS and Peter Deutsch's WHOIS++ distributed white pages directory.

People

One of the developers of WAIS was Brewster Kahle, who left Thinking Machines to found WAIS Inc in Menlo Park, California with Bruce Gilliat. WAIS Inc. was originally developed as a joint project between Apple Computer, Peat Markwick, and Thinking Machines. In 1992, the presidential campaign of Ross Perot used WAIS as a campaign wide information system, connecting the field offices to the national office. Later, Perot Systems adopted WAIS to better access the information in its corporate databases. Other early clients were the Environmental Protection Agency, Library of Congress, and the Department of Energy and later the Wall Street Journal and Encyclopædia Britannica.

(After selling WAIS to AOL in May 1995 for $15 million, Kahle and Gilliat founded the Internet Archive and Alexa Internet.) Following the sale, Margaret St. Pierre left WAIS Inc to start Blue Angel Technologies. Her "WAIS variant" formed the basis of MetaStar. François Schiettecatte left Human Genome Project at Johns Hopkins Hospital and started FS-Consult and developed his own variant of WAIS which eventually became ScienceServer, which was later sold to Elsevier Science.

WAIS and Gopher

Public WAIS was often used as a full text search engine for individual Internet Gopher servers, supplementing the popular Veronica system which only searched the menu titles of Gopher sites. WAIS and Gopher share W3's client-server architecture and a certain amount of its functionality. The WAIS protocol is influenced largely by the z39.50 protocol designed for networking library catalogs. It allows a text-based search, and retrieval following a search. Gopher provides a free text search mechanism, but principally uses menus. A menu is a list of titles, from which the user may pick one. While gopher space is a web containing many loops, the menu system gives the user the impression of a tree.

The W3 data model is similar to the gopher model, except that menus are generalized to hypertext documents. In both cases, simple file servers generate the menus or hypertext directly from the file structure of a server. The W3 hypertext model gives the program more power to communicate the options available to the reader, as it can include headings and various forms of list structure.

References

• RFC1625: WAIS over Z39.50-1988 M. St. Pierre, J. Fullton, K. Gamiel, J. Goldman, B. Kahle, J. Kunze, H. Morris, F. Schiettecatte, June 1994
• RFC 4156: The wais URI Scheme P. Hoffman, August 2005
• The Z39.50 Information Retrieval Standard Part I: A Strategic View of Its Past, Present and Future, Clifford A. Lynch, D-Lib Magazine, April 1997

External links

• Wide Area Information Servers (WAIS) launch lecture (1991)