To put together a prototype in the short time frame of two months, existing information search and retrieval tools were used. The prototype was designed to be accessed by the user from a HTML+ forms-capable World Wide Web (WWW) client, such as recent versions of NCSA Mosaic. The information and software were either already available on or were made available on a variety of network servers, including FTP, Gopher, WAIS, and HTTP.
Mosaic attempts to provide an interface to all the commonly used information retrieval services from a single application program. Mosaic retrieves an object from a network server and either displays it in a window, or if display is not possible or the user prefers, saves it to a disk file. A retrievable object may be stored in a file on a local or remote file system or may be constructed at retrieval time (for example, in response to a search query). An object is named by a string called a Uniform Resource Locator (URL). To retrieve an object, a user clicks on a highlighted anchor (which contains a URL) in a displayed document, specifies a URL to open, or fills in a form (causing Mosaic to generate a search URL). The URL contains the protocol to be used to contact the server, the server's DNS hostname, and any other information to be used by the server to locate or generate the object. The server typically returns either the object or an error message.
Mosaic provides native support for the FTP, Gopher, HTTP, and WAIS protocols. With WAIS, however, an alternative technique is to provide a WAIS-HTTP gateway which converts an HTTP search URL to a WAIS query, processes the query either locally or by contacting a remote WAIS server, and converts the search results to an HTML document.
Software may be made available through the NII by placing it on a file system served by FTP, Gopher, and/or HTTP servers. A software collection may be made searchable by WAIS-indexing descriptions of the software and running a WAIS server and/or by running an HTTP server and providing a WAIS-HTTP gateway. HTTP gateways may also be provided to other search engines, such as relational databases. With Mosaic, softare the user retrieves may either be displayed in a window and then saved to disk, or saved directly to a disk file. Only one file may be retrieved at a time, however.