7. A data driven validation system comprising: one or more processors; a memory; an abstract rule store stored in the memory linking one or more rule instance data items to one or more corresponding rules stored in a concrete rule store, each rule instance data item comprising a target data identifier identifying a data type of a target data item processed by its respective linked one or more corresponding rules, and at least one rule instance data item comprises a condition which is implemented as another rule instance data item and an exemption data item, prior to executing a corresponding rule for which the condition has been satisfied, accessible by the rule engine like any other rule instance data item and is attached to the one or more rule instance data items, wherein the another rule is independently executed to determine whether the at least one rule instance data item is to be executed; a validation software interface executing on the one or more processors for receiving a validation request comprising a target data object from an executing application, the target data object including one or more target data items of the object to be validated; a rule engine executing on the one or more processors for accessing the one or more rule instance data items communicatively coupled to the validation software interface to receive the validation request; the rule engine identifies one or more rule instance data items based on the target data identifier which are applicable to the one or more target data items; the rule engine executes rule logic, which is decoupled from a client device executing the application requesting the validation, and processing the one or more rule instance data items of the corresponding one or more rules linked to the identified one or more rule instance data items, without having to update the application wherein the target data object identifies each target data member item by a class identifier and a property identifier; and identifying a data type and any inherited data type for the one or more target data item members comprises determining data types and class membership based on identifying matches with the class identifier and the property identifier for each target data member item and the data type and any inherited data type.
12. The system of claim 7 wherein each rule instance data item of the abstract rule store comprises a target data identifier including a class identifier and a property identifier; the rule engine further comprises a rule validator which receives the target data object and each target data item of the object is identifiable by a class identifier and a property identifier; and the rule validator searches class and property identifiers of rule instance data items for a match.