—None of the current plethora of meta-modelling tools includes a complete, explicit model of themselves. Such a model, a precise specification of the tool’s syntax and semantics, allows for introspection and self-modifiability. These features enhance model debug-ability, make it easier to decompose the tool for distributed execution, and allow for reasoning about correctness and performance. In this paper, we present the foundations of the Modelverse, a self-modifiable environment for MultiParadigm Modelling (supporting multi-formalism and multiion modelling as well as explicitly modelled processes). We identify a set of requirements, which we believe are vital to a modern Multi-Paradigm Modelling tool. These requirements then are mapped to the features which our specification will support: self-modifiability, formalization, and multiple notions of conformance between models and meta-models.