comp.os.minix - join
Discussion of Tanenbaum's MINIX system.
Low activity, 1733 subscribers, Usenet

comp.os.inferno - join
The Inferno network operating system from Lucent.
Low activity, 51 subscribers, Usenet

plan9changes - join
Notification of changes and patches for the operating system Plan 9 from Bell Labs
Low activity, 159 members, restricted