FreeBSD 6.1-SECURITY #0: Mon Aug 28 05:21:08 UTC 2006 firstname.lastname@example.org:/usr/obj/usr/src/sys/GENERIC Timecounter "i8254" frequency 1193182 Hz quality 0 CPU: Pentium/P54C (199.43-MHz 586-class CPU) Origin = "GenuineIntel" Id = 0x52c Stepping = 12 Features=0x1bf
real memory = 33554432 (32 MB) avail memory = 23379968 (22 MB) Intel Pentium detected, installing workaround for F00F bug
Despite its age, CPU, and RAM, I am doing real work with it. Sure, I'm not serving Web pages or handling email, but I am testing IPv6. In fact, I just connected to IRC with it.
p200:/home/richard$ irssi -n user6 -c irc.ipv6.freenode.net ...edited... 22:14 -!- user6 [n=richard@2001:5c0:925d:0:204:5aff:fe79:43a7] has joined #snort-gui
Using FreeBSD Update I installed all binary patches, and I am adding binary packages with pkg_add. The SSH session is very responsive. I could not run the latest version of Windows XP on this box, and Windows Vista is Right Out (TM).
If you want to see just how "low can you go," check out this great post by Nikolas Britton on FreeBSD's minimum memory requirements. I expect to see it in official documentation soon.