&gt; the Perl 5 interpreter code base is widely considered unmaintainable these days<p>People love to say this, but having read a fair chunk of the sources to perl5, cpython, ruby, Tcl and erlang&#x27;s VMs, my semi-educated conclusion is &quot;reasonably fast interpreters written in portable C all end up as their own slightly bizarre CPP-supported C dialect, and all end up more similar than they are different&quot;.