Back in December 2008, I began a detailed critique of John Maynard Keynes' The General Theory of Employment, Interest and Money (1936). One of the reasons I gave for undertaking this task was because "to the best of my knowledge, there is no such commentary available online."
It turns out I was wrong.
Henry Hazlitt beat me to it with The Failure of the New Economics (1959) by some 50 years! Murray Rothbard contributed an excellent foreword to the book.
Mission accomplished (albeit not by me).