Enter Jeff McCune of Ohio State, with help from Christopher Suleski at Rutgers. Sensing the inherent injustice in this situation, Jeff has written up a thorough guide to getting NetBoot working with a Linux server, using the CentOS distribution and a slew of open source tools. While previous guides have tackled NetBooting OS 9 clients from a Linux server, this is the first I've seen that addresses OS X for both PPC and Intel machines. Grab an old PC with two Ethernet cards and you're on your way to NetBoot nirvana.
Keep in mind that this is not a project for the faint of heart or wary of the CLI. As McCune indicates on his wiki, even experienced UNIX admins would probably spend a few hours getting everything just right. Compare your time cost vs. the old G4 tower you could probably draft into service and the price of a 10.4 Server 10-user license... you do the math.
[via Macenterprise.org mailing list]
Update 3:30 pm Sat: "Read" link corrected below via tinyurl (it's HTTPS, so it has to be redirected).