1. A system comprising: one or more computer-readable storage media; software instructions resident on the media which, when executed, are capable of representing a document with a markup representation comprising: a first element which logically binds an ordered sequence of pages together into a single multi-page document; and one or more second elements each of which is a child of the first element and refers to a source of content for a single page of the document, said elements being mappable to an associated object class and collectively defining a fixed payload, wherein the fixed payload has a fixed number of pages and a layout that is predetermined and wherein layout calculations do not have to be performed on a consuming device where content of the document can be rendered, and wherein the fixed payload has multiple fixed payload parts at least two of which are connected, each connected fixed payload part having an associated discoverable relationship part containing one or more relationships for which that associated connected fixed payload part is a source, individual relationships representing a connection and making the connection discoverable without parsing content of the fixed payload parts associated with the connection, the multiple fixed payload parts comprising: a root part; one or more a fixed page parts, each referenced by one of the one or more second elements and containing fixed page markup describing properties and additional elements associated with rendering document content; an image part representing one or more images within the document; and a font part describing one or more fonts used in the document.
1. A system comprising: one or more computer-readable storage media; software instructions resident on the media which, when executed, are capable of representing a document with a markup representation comprising: a first element which logically binds an ordered sequence of pages together into a single multi-page document; and one or more second elements each of which is a child of the first element and refers to a source of content for a single page of the document, said elements being mappable to an associated object class and collectively defining a fixed payload, wherein the fixed payload has a fixed number of pages and a layout that is predetermined and wherein layout calculations do not have to be performed on a consuming device where content of the document can be rendered, and wherein the fixed payload has multiple fixed payload parts at least two of which are connected, each connected fixed payload part having an associated discoverable relationship part containing one or more relationships for which that associated connected fixed payload part is a source, individual relationships representing a connection and making the connection discoverable without parsing content of the fixed payload parts associated with the connection, the multiple fixed payload parts comprising: a root part; one or more a fixed page parts, each referenced by one of the one or more second elements and containing fixed page markup describing properties and additional elements associated with rendering document content; an image part representing one or more images within the document; and a font part describing one or more fonts used in the document. 6. The system of claim 1 , wherein at least one of said properties is expressed as an XML attribute.