Summary form only given. In this paper we propose a new peer-to-peer protocol for atomic reliable multicast based on view consistency. It is designed for nearly real-time collaborative applications which require consistency of data in a group of participants. A typical example for this is drawing on a shared whiteboard. Collaborations frequently arise in an ad-hoc way in which setting up and operating a dedicated server is not feasible. Thus, our protocol is intended to be used in server-less environments and avoids dependence on central components. We implemented our protocol using the peer-to-peer middleware JXTA for use in TCP/IP-connected networks. This implementation offers its service to other applications via a lean Java API.