Surfing the Web backwards

From a user's perspective, hypertext links on the Web form a directed graph between distinct information sources. We investigate the effects of discovering `backlinks' from Web resources, namely links pointing to the resource. We describe tools for backlink navigation on both the client and server side, using an applet for the client and a module for the Apache Web server. We also discuss possible extensions to the HTTP protocol to facilitate the collection and navigation of backlink information in the World Wide Web.