The monography is a proceeding of the papers presented at the 3rd 3rd International Workshop on Model Driven Architecture and Modeling Driven Software Development In conjinction with the 6th International Conference on Evaluation of Novel Approaches to Software Engineering. The workshop is aimed at theoretical and practical aspects of OMG's Model DrivenArchitecture, the Modeling-Driven Software Development, and Model-Driven Engineering as well. The first Workshop "Model - Driven Architecture: Foundations, Practices and Implications (MDA 2009)" was organized in conjunction with the 13th Conference on Advances in Data Base and Information Systems (ADBIS 2009) in Riga (Latvia), the 2nd "Model-Driven Architecture and Modeling Theory-Driven Development - MDA & MTDD 2010" was organized in conjunction with the 5th ENASE 2010 conference in Athens (Greece).