I don't see the point in copying this answer whole into a blog post. It does not help to understand the "improved" in vim, as Jim Dennis' answer says he does not try to.

A blog post that quoted from Jim's answer and gave pointers to further information about vim's extensions would have begun to justify the title.

For reference value - HN post linking to Jim's answer: http://news.ycombinator.com/item?id=2911930