ISNIC's part in the partnership entails providing and hosting RcodeZero DNS server equipment in Iceland. Due to the geographically remote location of the country, the cooperation is particularly useful for Internet users on both sides of the Atlantic. The other two anycast DNS clouds, which have been handling the .IS for a long while already, are the Swedish Netnod, and the PCH (Packet Clearing House). Many hundreds of servers are now responsible for responding to DNS queries about .IS domains around the world.
Here is the news item about the cooperation at RcodeZero's website