Zach Amsden is a hacker working for VMware, with ninja MMU skills and a gory knowledge of the x86 architecture. He is also a practitioner of Ashtanga yoga, which he uses to pursue his goal of becoming one with the Linux kernel. He occasionally goes by the pseudonym Chaz Masden when he doesn't want people to know his true identity.
Jeremy Fitzhardinge is a hacker working for XenSource, who lead the integration of Xen on top of the kernel paravirt_ops.
Rusty Russell is a professional paper submitter who is riding on the back of the other's brilliance.
Chris Wright is a hacker working for RedHat to herd all the cats and get Xen into the kernel.