A server or other computing device can receive a request for a feed (e.g., Really Simple Syndication, Atom, or other Extensible Markup Language format feed) from a client. Content of the requested feed and a type of the client can be determined. Executable processing logic can be added into the requested feed according to the determined content of the feed and the type of the client. The feed into which the executable processing logic has been added can be sent to the client.