Friends of mine were wondering about the history after that seminal text: how we got from this (opinionated, but sensible approach) to agile coaches (they appar

Friends of mine were wondering about the history after that seminal text: how we got from this (opinionated, but sensible approach) to agile coaches (they apparently never had a good experience of any; I worked with one a long time ago, the guy was like a fish on a tree at that particular company). I realized I don't know all the parts: I've met a couple of influential people in that world but there are still a lot of trends that confuse me. Is there a history of modern software practices?