21. A computer readable medium comprising instructions that, when executed by a computer, perform a method having a step of identifying a hierarchy of markup language nodes that need to be inserted or deleted, and where they need to be inserted, when data is added to or deleted from a structured markup language document, wherein: the hierarchy of markup language nodes is an expression of all possible fragments of a hierarchical markup language that are to be inserted when rendering the structured markup language document by processing documents containing structured data that is expressed using the hierarchical markup language; and the expression of all possible fragments is encoded in a manifest file as a single markup language fragment that: includes respective sub-fragments having the maximum and minimum number of characters each corresponding to one or more said markup language nodes; and has less characters than a fragment containing all possible fragments; the structured markup language document has a syntax described by a schema; the manifest file encodes schema information from the schema to achieve schema awareness at edit time; and the identifying a hierarchy of markup language nodes further comprises using the manifest file having the single markup language fragment and the schema information at edit time to determine a corresponding portion of the single markup language fragment to be inserted or deleted, such that the data added to or deleted from the structured markup language document is valid with respect to the schema.
21. A computer readable medium comprising instructions that, when executed by a computer, perform a method having a step of identifying a hierarchy of markup language nodes that need to be inserted or deleted, and where they need to be inserted, when data is added to or deleted from a structured markup language document, wherein: the hierarchy of markup language nodes is an expression of all possible fragments of a hierarchical markup language that are to be inserted when rendering the structured markup language document by processing documents containing structured data that is expressed using the hierarchical markup language; and the expression of all possible fragments is encoded in a manifest file as a single markup language fragment that: includes respective sub-fragments having the maximum and minimum number of characters each corresponding to one or more said markup language nodes; and has less characters than a fragment containing all possible fragments; the structured markup language document has a syntax described by a schema; the manifest file encodes schema information from the schema to achieve schema awareness at edit time; and the identifying a hierarchy of markup language nodes further comprises using the manifest file having the single markup language fragment and the schema information at edit time to determine a corresponding portion of the single markup language fragment to be inserted or deleted, such that the data added to or deleted from the structured markup language document is valid with respect to the schema. 25. The computer readable medium as defined in claim 21 , wherein the structured markup language document is expressed in a markup language selected from the group consisting of Standard Generalized Markup Language (SGML), HyperText Markup Language (HTML), and eXtensible Markup Language (XML).