According to the documentation it is possible to run two robots on a single server:
Is it possible to run two hubs in this manner as long as the hub ports are specified individually? After all, the hub is essentially just a probe.
This has not been through extensive QA, but is indeed possible and theoretically there is no reason it should not work.
The key is to specify an alternate hub port in the hub.cfg (hubport key) other than 48002 (or when installing the hub.)
The only currently known drawback is that hubs which run on an alternate port cannot be configured using Infrastructure Manager directly, as it assumes 48002 for the hub port.