> For example, a simple tutorial featuring Virtual File System for Ruby
> (single united API for accessing Local FS, AWS S3, SFTP, กฤ) written
> using Literate Programming approach.
Huh, I forgot to add a link to it :), here it is http://alexeypetrushin.github.com/vfs

> But if we take out
> macros from the equation, then what makes literate programming different
> from writing code with comments?
1. If You write a book that contains code, the API of libraries may changed over time and Your book will be outdated, with literate programming You can "execute" Your book and instantly check that all the code there is correct.
2. It's like a mental shift, like BDD vs TDD, looks similar but not quite the same. With comments You write "how code works" with literate programming You describe main idea "why this code exists and why it works this way".