18. The system of claim 15 wherein when the modification to the first object comprises one of replacing the first object with a new first object, the vNode manager component is configured to generate a new first vNode corresponding to the new first object, wherein the new first vNode includes versioning information associated with the next version of the structured document, and store the new first vNode in the data store.
18. The system of claim 15 wherein when the modification to the first object comprises one of replacing the first object with a new first object, the vNode manager component is configured to generate a new first vNode corresponding to the new first object, wherein the new first vNode includes versioning information associated with the next version of the structured document, and store the new first vNode in the data store. 19. The system of claim 18 wherein when the first object is a next sibling of the sharable object and the vNode representing the sharable object includes information identifying a next sibling vNode representing the first object, the vNode manager component is configured to update the vNode representing the sharable object by adding information identifying the new first vNode representing the new first object of the next version of the structured document.