19. A computer-readable medium having stored therein computer usable program code for comparing a source document with a target document, each document is capable of being parsed into a DOM (Document Object Model) tree, the computer usable program code, which when executed by a computer hardware device, causing the computer hardware device to perform: parsing the source document into a source DOM tree; parsing the target document into a target DOM tree; creating a source leaf path table from the source DOM tree; creating a target leaf path table from the target DOM tree, each of the tables containing leaf paths which comprise nodes; generating a comparison of the source document with the target document by identifying entries, within the target leaf path table, that exactly match entries in the source leaf path table, for each match found, labeling as exactly matched the corresponding source and target leaf paths, and for only those leaf paths that have not been labeled as exactly matched, identifying whether or not schema matches exist between those leaf paths present in the source leaf path table and those leaf paths present in the target leaf path table; and outputting to a user the comparison of the documents.
19. A computer-readable medium having stored therein computer usable program code for comparing a source document with a target document, each document is capable of being parsed into a DOM (Document Object Model) tree, the computer usable program code, which when executed by a computer hardware device, causing the computer hardware device to perform: parsing the source document into a source DOM tree; parsing the target document into a target DOM tree; creating a source leaf path table from the source DOM tree; creating a target leaf path table from the target DOM tree, each of the tables containing leaf paths which comprise nodes; generating a comparison of the source document with the target document by identifying entries, within the target leaf path table, that exactly match entries in the source leaf path table, for each match found, labeling as exactly matched the corresponding source and target leaf paths, and for only those leaf paths that have not been labeled as exactly matched, identifying whether or not schema matches exist between those leaf paths present in the source leaf path table and those leaf paths present in the target leaf path table; and outputting to a user the comparison of the documents. 26. The computer-readable medium of claim 19 , wherein the outputting provides annotations on both the source leaf path table and the target leaf path table to indicate matching and non-matching portions resulting from the comparison of the two documents.