The Internet Software Consortium, maintainers of a DHCP server, can be found at www.isc.org.
H. Peter Anvin's SYSLINUX Project, the source of PXELINUX, is at syslinux.zytor.com.
tftp-hpa can be found at www.kernel.org/pub/software/network/tftp or at your friendly neighborhood kernel mirror site.
Richard Gooch developed the device filesystem for Linux; his Web site is at www.atnf.csiro.au/people/rgooch/linux/index.html
Erik Anderson maintains the BusyBox combined binary at www.busybox.net.
A companion Web site for this article with a downloadable X Terminal Kit is at frank.harvard.edu/~coldwell/diskless.