grammars. These grammars allow nesting rules to be defined using the Oniguruma regular expression library, and then assigned specific "scopes": compound labels which identify them for coloration.

Each point of a document is assigned one or more scopes, which define where in the document the point is, how it should be colored, and what the behavior of TextMate should be at that point. For instance, the title of one of the links in the "External links" section