A method and apparatus are disclosed for providing persistent storage of
Web resources. Uniform Resource Locators ("URLs") that identify Web
resources are augmented to include a time stamp. A web browser and a web
server are disclosed that accommodate a time stamp parameter and allow a
user to refer to any Web address with a precise target date. The
disclosed Web browser can optionally include a mechanism to facilitate
the specification of the desired date and time, or the user can manually
append the time stamp to the URL indicated in the "Location" window of
the browser. The persistent Web servers (i) receive URLs containing a
time stamp, relative or variable time-stamp, (ii) extract the time stamp,
(iii) retrieve the appropriate Web page(s) corresponding to the
time-stamp, and (iv) return the appropriate page(s) or links to the
client. Wildcard characters and date ranges can be used in the variable
time-stamp to implement a variable time stamp when a user is not sure of
the date for a specific web resource or wishes to specify more than one
precise date and time. The persistent Web servers include a persistent
archive for storing all of the versions of Web resources that will be
persistently available to Web users.