• comp.os.aos (newsgroup)
• comp.os.chorus (newsgroup)
• comp.os.coherent (newsgroup)
• comp.os.cpm (category)
• comp.os.geos.misc (newsgroup)
• comp.os.lantastic (newsgroup)
• comp.os.linux (category)
• comp.os.lynx (newsgroup)
• comp.os.mach (newsgroup)
• comp.os.magic-cap (newsgroup)
• comp.os.minix (newsgroup)
• comp.os.misc (newsgroup)
• comp.os.ms-windows (category)
• comp.os.msdos (category)
• comp.os.netware (category)
• comp.os.os2 (category)
• comp.os.os9 (newsgroup)
• comp.os.parix (newsgroup)
• comp.os.plan9 (newsgroup)
• comp.os.qnx (newsgroup)
• comp.os.research (newsgroup)
• comp.os.rsts (newsgroup)
• comp.os.v (newsgroup)
• comp.os.vms (newsgroup)
• comp.os.vxworks (newsgroup)
• comp.os.xinu (newsgroup)