The limitations of client/server systems become evident in an Internet-scale distributed environment. Peer-topeer (P2P) systems offer an interesting alternative to traditional client/server systems: Every node acts both as a client and a server and “pays” its participation by providing access to its computing resources. Systems such as Napster and Gnutella have proven their practical applicability. In this article we give an overview of our PGrid system which provides an advanced P2P infrastructure targeted at application domains beyond mere filesharing. We present the conceptual foundations and outline some of the applications we are developing at the moment.