I tried out portmaster recently. Coming from rethinkdns on Android, I was far from impressed; it looks featured, but it's much harder to use. Opensnitch looks better but doesn't have the nice features to drill down connections (get from app requesting a domain being resolved to an IP and connecting on a port, and filter this at any level including globally; if the request was already filtered, you can see why and get to that filter to either remove it or add an exception)

ZoneAlarm, assuming it still exists, would be at least 20 years old.

Back then there was also a nice ~$15 program called Net Limiter which allowed one to cap network speeds individually per program.