ringmaster

noun

1. The person who manages the performers in a circus ring.
2. (Internet)The person who maintains a webring.

   “Individuals looking to add their own homepage to a particular ring are, however, more or less at the mercy of the ringmaster, who often maintains a ring homepage listing its acceptance (or membership) policies and an index of its member sites.”

   “Each of the member websites in a webring had a navigation area at the bottom of the page that had “next” and “previous” buttons directing surfers to other sites in the ring. […] People needed ringmasters because the number of sites aimed at women was exploding.”

verb

1. To act as ringmaster.
2. (figuratively)To control (a group of people).