Grammatic is a tool for grammar definition and manipulation aimed to improve modularity and reuse of grammars and related development artifacts. It is independent from parsing technology and any other details of target system implementation. Grammatic provides a way for annotating grammars with arbitrary metadata (like associativity attributes, semantic actions or anything else). It might be used as a front-end for external tools like parser generators to make their input grammars modular and reusable. This paper describes main principles behind Grammatic and gives an overview of languages it provides and their ability to separate concerns and define reusable modules. Also it presents sketches of possible use cases for the tool.