Almost four decades have passed since Formal Grammars first appeared in 1974. At that time it was still possible to rather comprehensively review for (psycho)linguists the relevant literature on the theory of formal languages and automata, on their applications in linguistic theory and in the psychology of language. That is no longer feasible. In all three areas developments have been substantial, if not breathtaking. Nowadays, an interested linguist or psycholinguist opening any text on formal languages can no longer see the wood for the trees, as it is by no means evident which formal, mathematical tools are really required for natural language applications. An historical perspective can be helpful here. There are paths through the wood that have been beaten since decades; they can still provide useful orientation. The origins of these paths can be traced in the three volumes of Formal Grammars, brought together in the present re-edition. In a newly added postscript the author has sketched what has become, after all these years, of formal grammars in linguistics and psycholinguistics, or at least some of the core developments. This may provide further motivation for the reader to make a trip back to some of the historical sources.