The TOPS-10 System was a computer operating system from Digital Equipment Corporation (DEC) for the PDP-10 released in 1964.

TOPS-10 had an interesting scheduler of having many run queues, unlike OpenVMS for example which has two run queues, and inserts processes into the queue depending on process priority. The TOPS-10 Operating System also included User file and Device independence. Code concepts developed for TOPS-10 ended up in RSX-11 that ultimately ended up in OpenVMS. These same operating system design ideas can probably be traced to current operating systems like Microsoft's Windows NT.

It featured one or two interesting Easter eggs. For example, the command

MAKE LOVE

gave the response

Not War?