• Current version of Chimera:  v1.20, for both Linux and Windows
  • Thanks to Serge Kruppa, who modified Chimera 1.10 to make it compatible for Windows XP.  A WinXP release of Chimera 1.10 is available.
  • Thanks to Perry Lorier for a patch to make Chimera compatible w/ 64 Bit machines!


Structured peer-to-peer overlays, sometimes also referred to as Distributed Hash Tables (DHTs), are scalable network infrastructures that support Internet-scale network applications utilizing a decentralized resource model.  At their core, these overlays provide Key-Based Routing (KBR), where messages addressed to any Key will incrementally route towards an overlay node responsible for that key.  On top of the KBR layer, these overlays can support distributed storage using a DHT layer or data location using a DOLR layer.

Along with Pastry, Chord, and CAN, Tapestry was one of the first structured overlay networks proposed in 2001. Since then, at least 20 structured protocols have been proposed with varying properties, including SkipNet/SkipGraph, Kademlia, Viceroy, Z-Ring among many others.  On top of these overlays, researchers have proposed numerous distributed applications, including distributed storage and backup systems, multicast systems, resilient routing networks, distributed spam filters, mobility support and anonymous routing networks.

Chimera is a light-weight C implementation of a "next-generation" structured overlay that provides similar functionality as prefix-routing protocols Tapestry and Pastry.  Chimera gains simplicity and robustness from its use of Pastry's leafsets, and efficient routing from Tapestry's locality algorithms.  In addition to these properties, Chimera also provides efficient detection of node and network failures, and reroutes messages around them to maintain connectivity and throughput.  

Along w/ academic research, Chimera is currently being used by projects at industry labs, as part of DoD research, and by local startups.  It also provides a research infrastructure for both graduate and undergraduate networking class projects at UCSB.  Three MS graduates have used it for their MS projects.  To get timely (but infrequent) notifications of updates, bug fixes and new releases to Chimera, please join the Chimera-users GoogleGroup.

Please note: development and support of the Java implementation of Tapestry has terminated, with the latest version being Tapestry 2.01.