Building a GeoIP server with ZeroMQ

"I discovered ZeroMQ while researching Mongrel2 and thought it was worth deeper investigation. At my day job, we have lots of services that don't scale well inside our front end stack, so we expose them as a service that each front end consumes. Some examples: search, memcache, geoip resolution, geo targeting, compatibility between users, etc. Basically, anything that relies on state that is expensive to duplicate on each front end becomes a service."

Read more here.