The i* (i-star) framework has been widely adopted by the information systems community. Since the time it was proposed, different variations have arisen. Some of them just propose slight changes in the language definition, whilst others introduce constructs for particular usages. This flexibility is one of the reasons that makes i* attractive, but it has as counterpart the impossibility of automatically porting i* models from one context of use to another. This lack of interoperability makes difficult to build a repository of models, to adopt directly techniques defined for one variation, or to use i* tools in a feature-oriented instead of a variant-oriented way. In this paper, we explore in more detail the interoperability problem from a metamodel perspective. We analyse the state of the art concerning variations of the i* language, from these variations and following a proposal from Wachsmuth, we define a supermetamodel hosting identified variations, general enough so as to embrace others yet to exist. We present a translation algorithm oriented to semantic preservation and we use the XML-based iStarML interchange format to illustrate the interconnection of two tools.Peer ReviewedPostprint (author's final draft
