The proliferation of the Internet, in particular the World Wide Web (hereinafter the Web), makes a large amount of information accessible to anyone connected to the Internet. In order to access the Internet, a user typically subscribes to an on-line service provider. Using, for example, a modem coupled to a computer, the user contacts the service provider who, in turn, connects the user to the Internet. Once the user is coupled to the Internet, the user is said to be "on-line" (a user who is not on-line is referred to as being "off-line"). When on-line, the user is able to access numerous resources available through conduits such as, for example, the Web.
The Web consists, generally, of voluminous "sites". Various Web sites contain information of virtually innumerable type, style, and content. Web sites are often comprised of a plurality of Web documents referred to as Web pages. In general, the layout language for a Web document is Hypertext Markup Language (HTML). Web documents are stored in HTML format in association with "server" software on remote servers. A Web document is given a "Uniform Resource Locator" (URL) which is essentially an address path identifying the server which hosts the desired document plus the location of the document on the server. Using "browser" software, an end-user can send a request from a client computer to access a document stored at a particular URL. Browser software such as Netscape.TM. Navigator, of Netscape Communications Corporation of Mountain View, Calif., is well known and widely available. When the server receives the user's request, it sends the requested HTML Web document to the client where the document can be displayed. The communications protocol used in making such a request and in transferring Web documents is "Hypertext Transfer Protocol" (HTTP). For more information about the Web, see for example T. Berners-Lee, R. Cailliau, A. Loutonen, H. F. Nielsen, and A. Secret, "The World Wide Web," Communications of the ACM, vol. 37(8), August 1994.
As a theoretical example of a Web site, consider a particular business, Business A, having a Web site dedicated expressly to providing information about Business A. Business A's Web site may contain an introductory Web page describing the general technologies and product areas in which Business A is involved. The introductory Web page may also contain links to other Web pages related to Business A. For example, the introductory Web page may have a link to a separate Web page disclosing financial aspects, such as the annual report, stock price history, and the like, of Business A. By selecting the link, the linked Web page is sent to the client computer and displayed to the end user. Thus, a user initially contacting Business A's introductory Web page may discover various other information about Business A by virtue of the linked nature of the Web.
Although a linked Web document is probably related to the original Web document, the linked Web document may reside separately from the original Web document. That is, the linked Web document may reside in a directory which is physically separate from the directory in which the original Web document is stored. In fact, the linked Web document may even reside in a computer or in hardware separate from the computer or hardware in which the original Web document is stored. Therefore, multiple Web documents may be linked even when the Web documents are not stored contiguously or even proximately. Separate storage of linked Web documents may result from the fact that a particular storage device does not have the capacity to contain all of the linked documents, or from the fact that a collection of linked web documents are maintained and/or owned by another individual and/or company.
Although on-line Web sites have substantial utility as information providers in both personal and professional environments, on-line access is not available to many potential end-users. For example, in government or high security environments, computing terminals are "quarantined" or isolated from the outside world. In such instances, on-line access is not available or is prohibited. Additionally, on-line access is often simply not feasible for any one of numerous reasons. For example, an end-user's hardware/computer system may not be adapted for on-line use, or may operate too slowly to effectively convey information to the end-user over an on-line connection. Likewise, if an end-user's client computer is located very distantly from the server system, on-line access may be prohibitively slow. As yet another example, during peak Internet or on-line use periods, response from the server system may be so greatly delayed as to render on-line retrieval of information impractical.
Thus, a need exists for a system which allows end-users to access Web site information, or other types of information commonly presented in an on-line manner, when the end-user is off-line. A further need exists for a system in which an off-line end-user can access linked information even when the linked information is so voluminous as to necessitate storage on multiple storage devices. Still another need exists for a system in which an off-line end-user accesses information in a manner which emulates on-line retrieval of the information.