Tapestry is a peer to peer, wide-area decentralized routing and location network infrastructure developed at University of California at Berkeley by Zhao et al.  Tapestry forms an overlay network that sits at the application layer (on top of an Operating System).  If tapestry is installed on different network nodes it will allow any one node to route messages to any other node running tapestry, given a location and a network independent name.  Also nodes in a Tapestry network can advertise location information about data it possesses in a specific format understood by other nodes running tapestry.  This special format allows the other nodes to find and access this data easily and efficiently, given that they know the data name.  So, we can see that tapestry allows nodes the ability to share data, thereby creating their own p2p system.

Advantages:

• Knows Network: tapestry has an advantage over Chord protocol because the algorithm knows the network topology, so queries never travel more than the network distance required to reach them
• Performance: like Chord, the look up time for tapestry protocol is lg(n)
• Distributed: does not require a centralized server

DISAdvantages:

• Scalability: does not handle node joins and failures as well as chord as it is more complicated.  So, chord is better for p2p systems with many nodes arriving and departing at random intervals.

    Pastry is not a food sold at the bakery! Pastry is a generic peer-to-peer content location and routing system based on a self-organizing overlay network of nodes connected via the Internet. Pastry is completely decentralized, fault-resilient, scalable, and reliably routes a message to the live node.

Advantages:

• Knows Network: like tapestry, pastry takes into account network locality; it seeks to minimize the distance messages travel, according to a to scalar proximity metric like the number of IP routing hops.
• Performance: like Chord, the look up time for tapestry protocol is lg(n)
• Distributed: does not require a centralized server
• Scalability: handles node arrivals and departures well, unlike tapestry

DISAdvantages:

• Complexity: like tapestry, pastry has a more complicated join protocol.  A new node's routing table will be populated with information from nodes along the path taken by the join message.  This leads to latency.

Advantages:

• Anonymous Nodes: allows nodes to be anonymous, so all nodes do not need to have id's.  In chord, however, all nodes need to have ids.
• Malicious nodes: malicious nodes are less likely to bring down the whole network.

DISAdvantages:

• Data Lookup: both applications perform data lookups using user supplied keywords, which presents difficulties.  User supplied keywords can be vague and incomplete, leading to failures and excessive delays in data lookups.
• Single Point of failure: napster uses a central index server which represents a single point of failure.  If this server goes down, users of napster can no longer perform any lookups.
• Network Congestion: Gnutella floods queries over the entire system, leading to high processing costs and network congestion