Transparency, collaboration, security, and digital sovereignty are the open source values that are also important to many European countries and institutions. Open source software offers practical advantages, cost savings, and opportunities for innovation that contribute to the region’s technological advancement and competitiveness, as well as fosters collaboration among developers and encourages innovation. On top of these values, several European projects try to build a sustainable and innovative future. In this paper the authors present two examples of an open source applications of meta-operating system (metaOS). The first NExt generation Meta Operating systems (NEMO) builds the future of the Artificial Intelligence of Things (AIoT)-edge-cloud continuum by introducing an open source, modular and cybersecure metaOS. The second regards the open source solutions provided by the NEPHELE Project to assist orchestration of distributed applications across resources in the computing continuum. In this matter, the open source components of the metaOS projects are presented for each functional layer in the architecture, demonstrating the value of open source for the metaOS sustainability in a specific use case.