1. A computer method for generating model-to-model transformations from one domain having a respective structured hierarchy to a second domain, comprising the steps of: having a given domain and a target domain, at least the given domain having a respective structured hierarchy, enabling a user to model and specify a transformation declarative in response to the user specified transformation declarative, creating a declarative mapping between a domain specific language modeling the given domain and a modeling language modeling the target domain, the declarative mapping specifying how the domain specific language modeling the given domain relates to the modeling language of the target domain; using the declarative mapping, generating a transformation code implementation of transformation from the given domain to 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 outputting instances of models of the target domain resulting from the performed transformation at runtime.