CMMI Guidelines for Process Integration and Product Improvement

CMMI Guidelines for Process Integration and Product Improvement
Author: Mary Beth Chrissis, Mike Konrad, Sandy Shrum
I bet that 90% of XP fans never read the book throughly. CMMI is very heavy, but it is definitely valuable at the same time. Every reader can benefit from it. I don't advocate for the model, but at least there are pretty good practice meaningful to project implementation.
It is too difficult/expensive to perform all practices presented in CMMI. The more efforts spent on process, you can't expect equally better output, there must be a peak point.