Indeed, I suspect it's a reasonable bet that the guy (Korban) just used the apache.org page and reformatted the contents with his target audience and personal goals (which seems to be selling his book) in mind.

[Which is not a bad thing, mind you—the apache page is fairly accurate and up-to-date (at least for the major compilers), so it's better people use that as a reference than doing it themselves badly. It would have been nice if he'd included a link though ...]

Which also has nice links to the specs for each feature.