Redo from scratch is an idea that is antithetical to reuse. Instead of modifying an existing program to fit a new purpose, a completely new program is written from scratch.

The philosophy of Chuck Moore, the author of Forth, has very strong RFS elements. Instead of deciding a set of standard pieces to build software from, Moore was ready to rethink just about any previous decision. What came to be the time-tested core of the Forth language was based on constant and obsessive rethinking, experimentation and redoing-from-scratch.

In practical purposes, RFS often has huge risks and problems, starting from the bugginess typical of new programs. However, it can be heartily recommended as an artistic or educational practice, as a way to exercise one's programming skills, or as a research method for experimenting with completely new ideas.