1. A system for processing XML documents, comprising: processing resources including at least one processor, a memory, and a non-transitory computer readable storage medium; wherein the processing resources are configured to: parse an XML document into one or more constituent nodes, the XML document including a plurality of objects representable in accordance with an object model, the XML document being parsed without also instantiating the objects therein; store the parsed constituent nodes and associated metadata in one or more partitions, each said partition having an associated commit level that initially is set to 0; store, for each said partition, an identifier thereof in a partition table list, the identifier(s) in the partition table list collectively identifying the working contents of the XML document, the partition table list initially being designated as a current partition table list and initially being designated as having a current commit level of 0; and manage atomic updates to the XML document in connection with a stack configured to hold one or more previous partition table lists.