9. A data processing system, comprising: a template repository storing one or more original templates, each original template being an electronic document that contains one or more data binding elements, each data binding element being a document element that includes a link to a respective external resource, the template definition identifying at least one of multiple data bind node classes, each data binding element in an original template having an original hash associated with the data binding element and derived from content of the data binding element in the corresponding original template; a template editor, the template editor being a computer program installed on the data processing system, the template editor being operable to create, copy, read, modify, and write templates for use by the template processor, the template editor being further operable to interact with a user to receive and perform commands from the user to modify a template, including commands to add, modify, and delete data binding elements from the template, wherein a modification is a major modification at least if it edits or adds any data bind node having the identified data bind node class, and wherein the modification is a minor modification if it does not edit or add any data bind node having the identified data bind node class, wherein the template editor is not operable to derive an original hash for a modified or new data binding element; and a validation module, the validation module being operable to parse a first template in use by the system, to identify every data binding element in the first template having the identified data bind node class, to calculate a separate verification hash for every data binding element in the first template, and to identify the first template as having the minor modification if every data binding element in the first template having the identified data bind node class is associated with an original hash that is identical to the separate verification hash calculated for the data binding element and identify the first template as having the major modification at least if any data binding element in the first template lacks an association with an original hash that is identical to the separate verification hash calculated for the data binding element.
9. A data processing system, comprising: a template repository storing one or more original templates, each original template being an electronic document that contains one or more data binding elements, each data binding element being a document element that includes a link to a respective external resource, the template definition identifying at least one of multiple data bind node classes, each data binding element in an original template having an original hash associated with the data binding element and derived from content of the data binding element in the corresponding original template; a template editor, the template editor being a computer program installed on the data processing system, the template editor being operable to create, copy, read, modify, and write templates for use by the template processor, the template editor being further operable to interact with a user to receive and perform commands from the user to modify a template, including commands to add, modify, and delete data binding elements from the template, wherein a modification is a major modification at least if it edits or adds any data bind node having the identified data bind node class, and wherein the modification is a minor modification if it does not edit or add any data bind node having the identified data bind node class, wherein the template editor is not operable to derive an original hash for a modified or new data binding element; and a validation module, the validation module being operable to parse a first template in use by the system, to identify every data binding element in the first template having the identified data bind node class, to calculate a separate verification hash for every data binding element in the first template, and to identify the first template as having the minor modification if every data binding element in the first template having the identified data bind node class is associated with an original hash that is identical to the separate verification hash calculated for the data binding element and identify the first template as having the major modification at least if any data binding element in the first template lacks an association with an original hash that is identical to the separate verification hash calculated for the data binding element. 14. The system of claim 9 , wherein each link of a data binding element comprises a Uniform Resource Locator (URL).