Systems and techniques to preserve state information in a client-server environment. In general, in one implementation, the technique includes: storing, in a shared memory of a client, a scripting object that retains state information for an original document, and cloning the stored scripting object to a newly loaded document. Storing the scripting object can involve copying a scripting object reference to the shared memory to cause retention of the scripting object by the client during document loading. Cloning the stored scripting object to the newly loaded document can be performed recursively, and can involve creating a new scripting object in the new document and copying data from the stored scripting object to the new scripting object. The state information retained in the scripting object can be navigation information associated with the loaded document, and the loaded document can be a portal page in a portal system.