Actually, FWIW, as far as the non-system stuff goes, John wrote the Mythos chapter (probably the best chapter in the book) and some of the Gamermaster chapter, as well as the End of Paradise scenario. Ken Hite, Scott Glancy, and I worked on the Gamermaster, Stories and Settings chapter (I no longer remember who wrote what exactly among that stuff).
For the system stuff, I wrote the first 7 chapters (John Crowe wrote most of the gun stuff in Chapter 6), the Little Slices of Death scenario, and all the appendices. Bruce Cordell and John Rateliff did the initial conversion of most of the monsters in Chapter 8, although I developed the final version of them as well.
I bring this up mostly because I don't think the other writers who worked on the book beyond John and I get enough credit.