In the Downloads section there is material covering Matrix Graph Grammar theory including its setup and its application to problems such as applicability, sequential independence and reachability.
For future research my intention is to continue with three further interesting problems: termination, confluence and complexity. I am currently dedicated to these tasks, more focused on complexity theory and the study of Matrix Graph Grammars as a model of computation. A first step in this direction has succesfuly established a link between Matrix Graph Grammars and Complex Analysis (the paper can be found here).
In the near future I shall try to write a continuation of the Matrix Graph Grammars Book (here if you want to download it for free, or here if you want to buy it). This second part will hopefully contain some extensions and generalizations of Matrix Graph Grammars.
If your interests are focused on discrete mathematics/theoretical computer science, there is still a huge research field on Matrix Graph Grammars. Contributions are absolutely welcome (needless to say that authoring will be respected). There are several things that you can do: