Actually, as I understand it, in V8 much of the core library is implemented in Javascript, compiled at build time, and then dumped into a library which can be linked in directly.<p>That is, a big chunk of it is explicitly AOT compiled JS, a bit like a Smalltalk image.<p>( see <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=294618" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=294618</a> )