Techniques for manipulating URIs that have been rewritten for XmlHttpRequests (XHRs) and/or Web Services for Remote Portlets (WSRP). In one set of embodiments, a URI rewriter factory module is provided that is configured to determine and select a URI rewriter module based upon an input URI string. The input URI string may be, for example, in the form of a Javascript pseudo-protocol link, a remote proxy URI, or both. The selected URI rewriter module can then parse the input URI string to generate a URI object that has methods for manipulating the input URI string and for outputting the resulting manipulated URI as a string.