As a software engineering paradigm, Model-Driven Software Engineering (MDSE) enhances software development through effective abstraction concepts, offering significant advantages like increased productivity and establishing models as a single point of truth. Key artifacts in MDSE, software models (e.g., UML), are crucial for designing and developing large-scale projects. These models undergo constant maintenance, including extensions, corrections, and optimizations, which can lead to complexity and necessitate collaboration among multiple developers on shared models, known as Collaborative Modeling. This thesis introduces a Difference Language (DL) to address model difference representation in collaborative settings. The DL is meta-model generic, operation-based, reusable, applicable, and extensible, functioning as a family of domain-specific languages. Specific DLs can be generated from the meta-models of various modeling languages, allowing changes in instance models to be articulated in terms of DL through modeling deltas. Additionally, the approach includes a catalog of supplementary services that enhance the reuse of DL-based modeling deltas, broadening the application areas of DL. The concept is demonstrated through applications in concurrent and sequential collaborative modeling, as well as model history analysis, utilizing specific orchestrations of DL services.
