TOPS-10

/topsten/ , n. DEC 's proprietary OS for the fabled PDP-10 machines, long a
favorite of hackers but now long extinct. A fountain of hacker folklore; see
Appendix A. See also ITS , TOPS-20 , TWENEX , VMS , operating system.
TOPS-10 was sometimes called BOTS-10 (from bottoms-ten ) as a comment on the
inappropriateness of describing it as the top of anything.