Aside from a tiny VM written in C++, nearly all of Factor (http://factorcode.org/ http://factorcode.org/), including its parser, optimizing compiler, and code g

Aside from a tiny VM written in C++, nearly all of Factor (http://factorcode.org/ http://factorcode.org/), including its parser, optimizing compiler, and code generator, is written in itself. The author of Clay (http://tachyon.in/clay/ http://tachyon.in/clay/) is working on a new version of its compiler written in itself too.