The Ninth International Workshop on Multi-­Paradigm Modeling (MPM) was held this year (2015) in Ottawa, Canada as a satelite event of the MoDELs conference. The purpose of this workshop is to bring together researchers and practitioners in the area of Multi-Paradigm Modeling in order to identify possible points of synergy, common problems and solutions, tool building aspects and visions for the future of the area.

Topics of interest include, but are not limited to:

• Heterogeneity in models: multi-domain and multi-physics modeling, multiview modeling, multi-abstraction modeling;
• Heterogeneity in modeling languages: engineering of modeling language, modeling Models of Computation (MoCs), quality evaluation and usability of modeling languages;
• Multi-Paradigm Modeling techniques: model transformation, model composition, modeling cross-domain interactions, model-based detection of unanticipated interactions in heterogeneous systems, visualization of multi-paradigm models;
• Applications and experience with current MPM techniques, non-exhaustive list of domains: healthcare, smart cities, smart homes, automotive, future energy systems, human-computer interaction, etc.

This year we got very interesting discussions around the MPM4CPS core group topics such as semantic adaptation, consistency and abstraction.