22. A computer-implemented method for presenting versions of network resources, the method comprising: under the control of a network computing component executing on one or more physical computing components of a network computing provider, the physical computing components configured to execute specific instructions, retrieving, from an electronic data store, a plurality of historical representations of a network resource as previously obtained from a content provider, the plurality of historical representations obtained from the content provider in response to a plurality of browse session requests for the network resource received from a particular client computing device at one or more previous times, wherein the content provider is separate from the network computing component; determining at least one difference between at least two of the plurality of historical representations; and generating a user interface comprising an interactive timeline and at least two objects, each object of the at least two objects comprising a visual representation of a corresponding one of the at least two historical representations, wherein a first object of the at least two objects comprises a visual indicator of the at least one difference, wherein a second object of the at least two objects is at least partially obscured by display of the first object, and wherein display of the first object is at least partially replaced by display of the second object in response to a user interaction with the interactive timeline.
22. A computer-implemented method for presenting versions of network resources, the method comprising: under the control of a network computing component executing on one or more physical computing components of a network computing provider, the physical computing components configured to execute specific instructions, retrieving, from an electronic data store, a plurality of historical representations of a network resource as previously obtained from a content provider, the plurality of historical representations obtained from the content provider in response to a plurality of browse session requests for the network resource received from a particular client computing device at one or more previous times, wherein the content provider is separate from the network computing component; determining at least one difference between at least two of the plurality of historical representations; and generating a user interface comprising an interactive timeline and at least two objects, each object of the at least two objects comprising a visual representation of a corresponding one of the at least two historical representations, wherein a first object of the at least two objects comprises a visual indicator of the at least one difference, wherein a second object of the at least two objects is at least partially obscured by display of the first object, and wherein display of the first object is at least partially replaced by display of the second object in response to a user interaction with the interactive timeline. 25. The computer-implemented method of claim 22 , wherein determining at least one difference comprises obtaining data identifying the at least one difference.