Actors have been designed for loosely coupled concurrent systems based on asynchronous message passing. This model is of particular relevance for Internet-wide distribution, but cannot unfold its full potential due to the lack of a globally available messaging service for groups. We present a message-oriented publish/subscribe middleware that enables global group communication at near-IP performance. Based on this transparent group layer, we build libcppa, an Actor library with modular support for group semantics that is compliant to the new C++ standard.