11. The system of claim 6 , wherein the one or more second servers communicate with the one or more first servers over an HTTPS link.
6. A system for generating a platform-independent document comprising: a database system implemented using a server system, the server system including one or more processors and one or more storage devices, the database system configurable to implement a document-rendering service using one or more first servers of the server system and to implement an on-demand service using one or more second servers of the server system different than the one or more first servers; the document-rendering service configurable to: receive a request from the on-demand service to generate a platform-independent document based on a renderable web document, the request including markup language content for the renderable web document; provide the markup language content to a rendering engine of the document-rendering service, the rendering engine being configured to: parse the markup language content, generate one or more resource requests for resources identified in the parsed markup language content, and communicate the one or more resource requests; intercept the one or more resource requests communicated from the rendering engine; communicate the one or more intercepted requests, or one or more requests based on the intercepted requests, to the on-demand service; receive, from the on-demand service, resources retrieved based on the communicated one or more intercepted requests or the communicated one or more requests based on the intercepted requests; provide the received resources to the rendering engine, the rendering engine being further configured to generate the platform-independent document based on the markup language content and the provided resources; and provide the generated platform-independent document to the on-demand service; and the on-demand service configurable to: generate the renderable web document including the markup language content; communicate the request to generate the platform-independent document to the document-rendering service; receive the communicated one or more intercepted requests, or the communicated one or more requests based on the intercepted requests, from the document-rendering service; retrieve the resources identified in the communicated one or more intercepted requests, or the communicated one or more requests based on the intercepted requests; communicate the retrieved resources to the document-rendering service.