Extreme Programming done ByTheBook
I polled developers on a variety of newsgroups and forums and it would seem that practically nobody is doing VanillaXp. On the whole (more than 60% of the time) they do some of the practices some of the time. I have also observed that some teams who claim to be doing XP ByTheBook quite simply are not. As with so many other methods, its almost impossible to judge the effectiveness of the method as a whole because so few teams are doing the whole thing.
Boaby