I have Appel's book. I love the fact that I can get very expensive books "second hand". The same information without the high cost. Appel doesn't get paid but I

I have Appel's book. I love the fact that I can get very expensive books "second hand". The same information without the high cost. Appel doesn't get paid but I know from my experience with publishers that tech books almost never make money. 3000 copies puts a book in the top 1%. Carnegie Mellon teaches a compiler course using continuations so I'm not sure what's "old" about it.