Notes on Grothendieck topologies, fibered categories and descent theory
arXiv:math/0412512
Abstract
This is an introduction to Grothendieck's descent theory, with some stress on the general machinery of fibered categories and stacks.
114 pages. I have corrected a finite, but extremely high, number of errors that have been pointed out to me by various readers. These were mostly typos, but a couple were substantial