Reading this chapter is not necessary for programming with Gforth. It may be helpful for finding your way in the Gforth sources.
The ideas in this section have also been published in the following papers: Bernd Paysan, ANS fig/GNU/??? Forth (in German), Forth-Tagung ’93; M. Anton Ertl, A Portable Forth Engine, EuroForth ’93; M. Anton Ertl, Threaded code variations and optimizations (extended version), Forth-Tagung ’02.