9. A computer-accessible, non-transitory storage medium encoded with computer-readable instructions configured to cause one or more data processing apparatus to: establish a relationship between a partner and a hosted server system based on a received request from the partner; receive a request from a partner administrator to customize a container document to provide to a partner end user, the container document including a first level of content and configurations selected by the partner administrator; receive an identification of the partner end user with access to the container document from the partner administrator; serve a customized container document to the partner end user; and receive a request from the partner end user to customize the container document.
13. The medium of claim 9 , wherein the partner administrator can control one or more authentication methods used to authenticate the partner end user, which content providers are available for selection by the partner end user, and a degree of configurability of the container document by the partner end user.