The reference implementation serves 3 purposes: 1) It implements the whole thing, so it can be used as-is. 2) It serves as a reference for any questions that

The reference implementation serves 3 purposes: 1) It implements the whole thing, so it can be used as-is. 2) It serves as a reference for any questions that are unanswered by the spec. Yes, specs should ideally answer all questions themselves, but there has not been a spec written yet that does not have at least one unanswered question somewhere. 3) It serves as a way to test new implementations, because you can see if your new implementation is compatible with the reference implementation. If not, then you probably screwed something up somewhere.