Well, compiling C11 with a compiler that only supports C98, or GNU-C &quot;extensions&quot; in contrast to vanilla C, but there&#x27;s no runtime compatibility issues like with interpreted languages (if that is what you were getting at).<p>Also, there&#x27;s the problem with platform portability (in terms of compiler &quot;oddities&quot;, not system libraries) which I won&#x27;t get into, because it&#x27;s a hairy subject. :)