In the process of implementing a new computer language, the point at which the language is sufficiently effective that one can implement the language in itself. That is, for a new language called, hypothetically, FOOGoL, one has reached break-even when one can write a demonstration compiler for FOOGoL in FOOGoL, discard the original implementation language, and thereafter use working versions of FOOGoL to develop newer ones. This is an important milestone. See {My Favourite Toy Language}. [There actually is a language called FooGol].