@calbaker @dgar It is built on the same desire to break up the issues with first-past-the-post and single-seat constituencies.
There's a lot of details going into a voting system. Single Transferable Vote is made for a proportional appointment of seats, and basically becomes Instant Runoff Voting if there's only one seat.
I think what US activists mean when they propose Ranked Choice Voting depends on the activist. Some of them are proposing IRV.