&gt; To buy you what?<p>To get a powerful core language on top of which I can build anything in just a couple of hundreds of lines (e.g., a complete JavaScript - in order to get the rest of the libraries for free). Or a JVM. Or .NET CLR. Or whatever else.<p>&gt; And 5 kloc in &quot;several days&quot;? I doubt it.<p>I did this as an experiment once. From bare machine code on a new architecture, via a very basic Forth, to Lisp and then C and everything else. Did not take much time to do.<p>&gt; Link or it didn&#x27;t happen.<p>Did not publish it yet for a variety of reasons, but may include this JavaScript compiler in my next code drop soon, stay tuned (see my github).<p>&gt; Besides, there&#x27;s no point in using Forth if you&#x27;re gonna end up running your stuff in a &quot;compliant JavaScript implementation&quot;<p>The question was that having only Forth would not leave me crippled - I&#x27;ll get all the power I want in just few days. And this kind of JavaScript implementation is more than just JavaScript. It allows me to use anything coded in JavaScript seamlessly from any other language built on top of the same meta-language.