This is vintage Ward. He comes up with stuff that is so simple and so obviously useful that you immediately wonder why you didn't think of it.

I love how this takes a weakness (incorrect parsing) and turns it into a strength by making it interactive.

There's a part I'm not sure I'm clear on. Is this process completely automated? Or does it still require a human in the loop to iterate the grammar? I'm assuming it's the latter.

If it's completely automated, how does it choose what the subsequent rule to further refine the parsing is?

A human is in the loop, deciding what to dive deeper into.

This reads like it was written by an exploratory text generator. For example, at the end of one of the paragraphs we find the sentence "Is happy to read the whole file."

Very neat. Based on the work of http://en.wikipedia.org/wiki/Parsing_expression_grammar

You just made my day. This is fantastic.