&gt;there is a reason that C is the foundation of computing rather than Lisp. I don&#x27;t think anybody really thinks otherwise anymore.<p>C is not the foundation of computing.  Why would you say this?<p>&gt;Likewise, Scheme implementations have mutable hash tables, but they&#x27;re written in C and not Scheme.<p>A native code compiler written in Scheme would have its hash table implementation also written in Scheme.<p>&gt;I don&#x27;t know how you even write a hash table based on cons cells rather than O(1) indexing.<p>You wouldn&#x27;t do that!  Cons cells are not the only primitive data type!  Another primitive type in Scheme is the vector, which is a mutable array.<p>I&#x27;m sorry, but you greatly misunderstand Lisp and how compilers work.