My main guesses:<p>* multiple dispatch
* the meta-object protocol<p>And the thing is, these features are being used all the time, because the core language is built out of them. If you want to see how a language which is not built on these things runs (on the same vm implementation, I might add), I suggest you try nqp :-).<p><a href="https:&#x2F;&#x2F;github.com&#x2F;nqp&#x2F;nqp" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;nqp&#x2F;nqp</a>