hash tables, displays from Hashtable class headers, multiple pages HeaderStyle tag HeaderTemplate tag HTML controls, combining for custom controls output, saving and reusing Render method and templates transforming from XML HTTP handlers built-in, overriding file download handler, creating IHttpHandler interface image handlers, reusable reusable HTTP runtime parameters, web.config HTTP-specific information, access from classes HTTPContext.Current property, tracing and <httpHandlers> element HttpUnhandledException