Grammar Diff/Merge started as a tool to compare Coco/R grammars in different versions. Over time it escaped this limited purpose and evolved into a sophisticated difference and merge tool. Grammar Diff/Merge supports Coco/R grammars, Coco2 grammars as well as plain text. The different input formats are encapsulated into plug-ins and can be exchanged. It is possible to extend the tool to a new input language by implementing a scanner and a parser interface.
Compare an old Version of the Coco/R grammar to a newer one: