According to the JustLinux forum, the bloke who goes by the handle of Saikee used four disks in more than 149 partitions. He stuffed them all onto a machine based around a Asrock 939NF4G CPU motherboard, an AMD 64 3200 with 1024MB RAM.
He used Grub to boot all of the operating systems because he said that it was the only one capable of handing a large number of systems.
Saikee didn't have any access to a commercial boot loader and relied solely on the standard facilities within Linux.
The more bizarre thing is that Saikee
claims to use all these operating systems. He said that he started his Linux adventure a year and a half ago and since
then they have just been building up - a bit like plaque. His grub boots up three versions of DOS, three Windows, five
BSDs, two versions of Solaris, 97 Linux Distros.
Of course, while it might impress his girlfriend, his fellow geeks feel that he did miss some fairly interesting operating systems such as HURD-, QNX-, L3 or Mach-based operating systems, or any L3/L4 microkernel-based OSes.
More here. µ