A system and method for providing a low-latency reliable multicast protocol designed for time-critical clustered applications. Internet Protocol (IP) multicast is used to transmit data and recovers from packet loss in end-hosts using a repair mechanism involving the exchange of XOR repairs between receivers and across groups. The system and method of the present invention can be embodied in a scalable, reliable and fast multicast primitive that can be layered under high-level abstractions such as publish-subscribe, group communication and replicated service/object infrastructures.