What do you mean ?
I use XP-model for making add-ons. The only viable option, in some cases. I also use XP for all the small programs I create. They might have a template requirement documentations, but beyond the initial documents, it's XP all right.
For any larger software projects I participate in, no XP whatsoever. Everything is specified and then coded in. Saves mistakes, and all faults done are because of bad specifiers