13. The computer system of claim 11 , further comprising a digital signatures interface allowing digital signatures to be provided for each of the document sequence, the sub-documents, and the pages.
11. A computer system comprising: storage containing instructions and resources; a processor that implements the instructions to perform acts comprising: accessing a collection of resources specified for the creation of an XPS document, the XPS document based upon an extensible markup language; establishing individual pages from the collection of resources according to an XPS specification for a page; establishing at least one sub-document as a collection of the individual pages; establishing the XPS document as a collection of at least one sub-document, providing access to the document sequence via a document sequence writer interface and the method further comprising rendering the XPS document by providing access to the document sequence via a document sequence reader interface; defining global properties for the XPS document including accepting digital signatures for the XPS document; and providing an application programming interface that performs the acts of accessing the collection, establishing the individual pages, establishing the at least one sub-document, establishing the XPS document, and defining the global properties, the application programming interface comprises: providing a resource class that comprises the XPS resources; providing a page class that comprises the page reader interface and the page writer interface; providing a document class that comprises the document reader interface and the document writer interface; and providing a document sequence class that comprises the document sequence reader interface and the document sequence writer interface.