Not if you weight by use. C, C++, Java, Javascript, and C# all have specs. Among the most popular languages, it&#x27;s really only the scripting languages that have the &quot;as our implementation does&quot; perspective on specification. I&#x27;ve always used languages that have standard documents, and communities that think those standard document are very important, so rather than being unreasonable, I think of complete language documentation as the natural state of the world.<p>Incidentally, this isn&#x27;t really a criticism, but it&#x27;s precisely because I don&#x27;t see Rust as finalized that it isn&#x27;t. A language that&#x27;s finalized but not specified is just poorly documented.