What do you mean "a coordinator with no users"?... If I decided to coordinate Whirlpool coinjoins for free instead of charging the insanely expensive 5% of the pool size fee that Samourai does, it would allow many more Bitcoiners to coinjoin that wouldn't be able to afford to use Samourai's coordinator.
So that's why I'm wondering: Where can Bitcoiners find the open source code that Samourai uses for their Whirlpool coordinator so they can use it to run their own?