Leveraging Applications of Formal Methods, Verification and Validation. REoCAS Colloquium in Honor of Rocco De Nicola

The ISoLA 2024 proceedings constitutes contributions of the associated events held at the 12th International Symposium on Leveraging Applications of Formal Methods, ISoLA 2024, which took place in Crete, Greece, in October 2024. ISoLA 2024 provides a forum for developers, users, and researchers to discuss issues related to the adoption and use of rigorous tools and methods for the specification, analysis, verification, certification,construction, test, and maintenance of systems from the point of view of their different application domains. This volume, Part I, contains the proceedings of the Colloquium inhonor of Rocco De Nicola's 70th birthday, held jointly with the ISOLA2024's track on REoCAS (Rigorous Engineering of Collective AdaptiveSystems). Rocco De Nicola has significantly contributed to collectiveadaptive systems through novel approaches for their formal specification,analysis, and verification. The Colloquium features one homagepaper and 23 contributions from invited authors who reflected uponthese developments within the context of Rocco's much broader legacyin concurrency theory, distributed systems, domain-specific languages,service-oriented computing, and formal methods, exploring his recentcontributions to cybersecurity.