The fundamental precept of literate programming is that documentation should not be written after software development, but be an integral part of it. A literate programming source is primarily a document in which source is embedded; the source is extracted by the literate programming tool by a process called tangling, while the file is typeset by a process called weaving.
Unlike traditional documentation, whether it be design specifications, or,
code or user documentation, literate programming offers the opportunity
for the documentation and software to remain synchronised
because the two are lexically close and easy to maintain together.
Furthermore, the published sources not only match the software
exactly, but are sure to be complete.
2.1. Interscript