13. Computer apparatus for providing software development, model-to-model transformations from one software program domain having a respective structured hierarchy to a second software program domain, comprising: given a domain of a software program in software development and a target software program domain in software development, at least the given domain having a respective structured hierarchy, and the software development having model-to-model transformation from the given software program domain to the target software program domain; a declarative mapper, provided by a Model Transformation Authoring Framework (MTAF), executing on a processor and mapping between a domain specific language modeling software development design of the software program in the given domain and a modeling language modeling software development design of the software program in the target domain, the declarative mapper enabling a user to specify how the domain specific language modeling in the given domain relates to the modeling language of the target domain; a code generator executable on the processor and responsive to the declarative mapper, the code generator generating a transformation code implementation of transformation from a software development model of the software program in the given domain to a software development model of the software program in the target domain, the generated transformation code being executable to perform a transformation of the domain specific language of the given domain to the modeling language of the target domain, and the code generator able to augment the transformation code with more transformation logic that is unable to be expressed with the declarative mapper, wherein the MTAF provides to the user design decisions with respect to specification of the declarative mapping; and an output member outputting to a computer display instances of models of the software program in the target domain resulting from the performed transformation at runtime.
16. Computer apparatus as claimed in claim 13 further comprising a transformation configurer configuring the transformation before execution of the generated transformation code at runtime, such that the transformation includes any one or combination of: merging output models, chaining output models, instantiating text templates using the output models, persisting output models and other post processing actions on the output models.