DSLs don't need to be supported by a separate lexer/parser. Some (for better or worse) use standard formats like yaml or json. Some (ie embedded DSLs) are repre

DSLs don't need to be supported by a separate lexer/parser. Some (for better or worse) use standard formats like yaml or json. Some (ie embedded DSLs) are represented using terms defined in a programming language. Any naming of types, functions or variables that you do while solving a problem in software is creating a "language" of terms that are specific to the domain. A well-constructed fluent API can read a lot like what you would call a DSL. A configuration language in YAML is both YAML and a DSL for config.