In this paper, we overview our experiences of developing large set of open source tools in ECSEL JU European project called MegaM@Rt2 whose main objective is to propose a scalable model-based framework incorporating methods and tools for the continuous development and runtime support of complex software-intensive Cyber-Physical Systems (CPSs). We briefly present the MegaM@Rt2 concepts, discuss our approach for open source, enumerate tools and give an example of a tools selection for a specific industrial context. Our goal is to introduce the reader with open source tools for the model-based engineering of CPSs suitable for diverse industrial applications.