A system in which a plurality of content providers provide multiple resources to multiple clients, wherein each content provider provides at least some resources via one or more content sources associated with that content provider. A client requests a resource from a content provider, where the resources includes references to other resources of the content provider. Referenced resources are served to requesting clients from a shared content delivery network (CDN) formed from a plurality of servers distinct from content sources associated with said content providers. The content sources may be origin servers associated with the respective content providers. The referenced resources may be video content, audio content, text, image content, web pages, HTML files, XML files, files in a markup language, documents, hypertext documents, data files, and embedded resources.