eDonkey network

The eDonkey network, also called the eDonkey2000 network or eD2k, is a peer-to-peer file-sharing network created in 2000 by American developers Jed McCaleb and Sam Yagan. It was designed for the distribution of large files and for maintaining availability over extended periods. Unlike a conventional centralized download service, the network does not store its shared files in one central repository. Files reside on participating users' computers and are transferred directly between peers, while servers primarily provide communication, indexing, and search functions. The network's architecture combined decentralized file transfer with a mostly server-based discovery layer. Users connected client applications to one or more eDonkey servers, which helped them find files and locate other peers holding those files. Anyone with a suitable Internet-connected machine could operate a server, although the server software was proprietary freeware rather than open source. Server addresses changed frequently, so clients commonly refreshed their server lists. The original server implementation came from MetaMachine, the company associated with the eDonkey2000 client. Later, the Lugdunum-derived eserver family became dominant and was extended through reverse engineering and continued protocol development. A defining technical feature was content identification through a hierarchical MD4 hash. Files were divided into chunks of approximately 9.3 MB, with a separate checksum calculated for each chunk. The combined hash list produced a root identifier for the file. This allowed files with identical content but different names to be treated as the same object, enabled interrupted downloads to resume, and permitted completed portions to be shared before the entire file had arrived. The network also supported searches using names and secondary attributes such as size, extension, and bitrate. eD2k links, which encoded file identifiers and metadata, became a common way for external indexing sites to point users toward network content. The ecosystem included the original eDonkey2000 client, eMule, and numerous other clients and derivatives. eMule became especially important because it was open source, released under the GNU General Public License, and extended the network with functions such as protocol obfuscation, peer exchange, support for files larger than four gigabytes, and the Kad distributed network. Other clients included aMule, MLDonkey, Shareaza, Lphant, JMule, and several discontinued or specialized projects. These applications broadened support across Windows, macOS, Linux, Unix-like systems, and other environments. The network reached substantial prominence in the mid-2000s. In 2004 it reportedly surpassed FastTrack in usage, and contemporary estimates described millions of connected users, hundreds of millions or more shared files, and a server population numbering in the hundreds. Razorback2 became one of its best-known servers and was reported to support around one million simultaneous users. The network's prominence also made it a major target of copyright-enforcement organizations. Razorback2 was seized in Belgium in February 2006, while other prominent servers were later shut down following legal action and injunctions. MetaMachine discontinued the original eDonkey2000 client after agreeing in September 2006 to pay the Recording Industry Association of America to settle threatened copyright-infringement litigation. The company also agreed to stop distributing its software and to take steps intended to prevent continued file sharing through existing copies. By 2007, BitTorrent had become the Internet's more widely used file-sharing protocol, and reports in 2009 described eDonkey as still significant but declining. The network's practical legacy continued through eMule, Kad, compatible clients, and server implementations, although the original MetaMachine client and server software are no longer maintained.

The eDonkey network emerged in 2000 from the work of Jed McCaleb and Sam Yagan, who developed a peer-to-peer system intended to handle large files more effectively than many earlier sharing services. Its design separated file discovery from file delivery. Servers maintained information that helped clients search for content and locate sources, but the files themselves remained on users' machines and moved directly between peers. This gave the network a decentralized transfer model while retaining a practical, server-assisted directory structure. MetaMachine developed the original eDonkey2000 client and an associated proprietary server implementation. The client was distributed as freeware and became the best-known entry point to the network. Files were identified by a root MD4 hash derived from a sequence of chunk hashes. Each file was divided into chunks of 9,728,000 bytes, with a checksum for each chunk. This approach supported error isolation, resumable downloading, and rapid redistribution of partial files. It also meant that content, rather than a filename, formed the central identity of a shared object. The protocol was never comprehensively formalized in a stable public specification. Instead, its effective behavior developed through the interaction of clients and servers, especially the eDonkey-compatible server software later associated with Lugdunum and eserver. MetaMachine abandoned active development of its original server software, while Lugdunum's reverse-engineered implementation extended the protocol and preserved compatibility. By the late 2000s, eserver software was reported to power almost all active eDonkey servers. It remained closed source but was available without charge. The network expanded through a broad collection of compatible clients. eMule, released as free software for Windows and later usable on other platforms, became the most influential alternative client. Its open-source development enabled public inspection and rapid adoption of protocol improvements. Extensions included peer-to-peer source exchange, obfuscation intended to make protocol traffic less readily identifiable, and support for files exceeding four gigabytes. Clients such as aMule, MLDonkey, Shareaza, Lphant, and JMule brought the protocol to additional operating systems or combined it with other peer-to-peer networks. As server dependence created bottlenecks and exposed the network to disruption, successor and complementary systems appeared. MetaMachine developed Overnet as a successor protocol intended to reduce reliance on centralized server directories. The eMule project created Kad, a Kademlia-based distributed network, and added source-exchange mechanisms that allowed clients to continue finding and exchanging data with less dependence on the original server connection. These developments preserved parts of the eDonkey ecosystem even as the original server-centered model became more vulnerable. The network reached its greatest public prominence in the middle of the 2000s. It reportedly surpassed FastTrack in 2004. Estimates from around 2005 described roughly two to three million users on average, hundreds of millions to billions of shared files, and between 100 and 200 servers, although measurements varied and were difficult to verify. Razorback2 was particularly prominent and was reported to handle about one million simultaneous users. Its seizure by Belgian police on 21 February 2006, following a complaint involving the MPAA and IFPI, became one of the most visible enforcement actions connected with the network. The equipment was confiscated and the operator was arrested. The network also faced server impersonation and content-poisoning problems. Some servers reportedly manipulated searches, censored results, advertised fake files, or claimed unusually large user populations. Copyright-enforcement groups were reported to have operated imitation Razorback2 servers that returned no useful results, while anti-piracy technology companies pursued additional enforcement against users. These practices made network-size estimates and search reliability increasingly difficult to assess. In September 2006, MetaMachine agreed to pay $30 million to avoid potential copyright-infringement lawsuits from the RIAA. The agreement included discontinuing distribution of eDonkey software and measures designed to restrict the use of prior copies for file sharing. Further legal action affected major servers in 2007. By that point, BitTorrent had become more popular, and a 2009 assessment characterized eDonkey as the second most popular peer-to-peer protocol but in rapid decline. The original MetaMachine client and server software are no longer maintained, but eD2k-compatible clients, eMule, Kad, and related open-source projects continued the technical lineage.

• 2009

  Network reported to be declining

  [1]EDonkey networken.wikipedia.org

  Contemporary reporting describes eDonkey as still widely used but rapidly losing ground to newer protocols, especially BitTorrent.

• 2007

  Major servers are closed

  [1]EDonkey networken.wikipedia.org

  DonkeyServer and other prominent servers are shut down after legal action and a temporary injunction.

• 2006

  Razorback2 is seized

  [1]EDonkey networken.wikipedia.org

  Belgian police confiscate Razorback2-related servers in a high-profile copyright-enforcement action.

• 2006

  MetaMachine settles RIAA dispute

  [1]EDonkey networken.wikipedia.org

  MetaMachine agrees to a $30 million settlement and to end distribution of eDonkey software.

• 2004

  Reportedly surpasses FastTrack

  [1]EDonkey networken.wikipedia.org

  The eDonkey network reportedly becomes the Internet's most widely used file-sharing network after overtaking FastTrack.

• 2002

  Lugdunum server development becomes important

  [1]EDonkey networken.wikipedia.org

  MetaMachine abandons active development of its original server software, while the reverse-engineered Lugdunum implementation becomes the basis for later eDonkey-compatible servers.

• 2000

  Network launched

  [1]EDonkey networken.wikipedia.org

  Jed McCaleb and Sam Yagan create the eDonkey network as a peer-to-peer system focused on large-file sharing and long-term availability.

A large-file peer-to-peer distribution network emphasizing decentralized transfers, resumable downloads, persistent file availability, and broad client interoperability.

• Peer-to-peer protocol · 2000

  eD2k protocol

  The underlying protocol coordinates file search, source discovery, chunked transfers, hashing, and communication between clients and servers. Its practical specification evolved through compatible implementations rather than a single formal standard. Later extensions included peer exchange, obfuscation, and support for files larger than four gigabytes.

• Desktop client · 2000

  eDonkey2000

  The original MetaMachine client provided the primary user interface for connecting to eDonkey servers, searching for files, and exchanging data with peers. It was proprietary freeware, became highly popular during the network's growth period, and was later discontinued following MetaMachine's legal settlement.

• Open-source client

  eMule

  eMule is a free, open-source client that became the most influential implementation in the eDonkey ecosystem. It supports the eD2k network and introduced or popularized capabilities such as source exchange, protocol obfuscation, and integration with the Kad distributed network. Its code also enabled numerous forks and compatible clients.

• Network server software

  eD2k server software

  eDonkey servers act as search and communication hubs rather than repositories for the shared files. The original MetaMachine server was proprietary and no longer maintained. Lugdunum-derived eserver implementations later became dominant, adding protocol extensions while remaining closed source and freely available.

• Distributed peer-to-peer network

  Kad

  Kad is an eMule-developed Kademlia-based network intended to reduce dependence on conventional eDonkey servers. It provides a more distributed mechanism for locating sources and content and forms an important successor or companion technology within the broader eDonkey and eMule ecosystem.

• 2007

  Shutdown of major eDonkey servers

  DonkeyServer and other major servers were closed following legal proceedings and a temporary injunction, adding to the pressure on the server-dependent portion of the network.

  Source

• 2006

  Razorback2 server seizure

  On 21 February 2006, Belgian police confiscated servers associated with Razorback2 at a datacenter near Brussels and arrested its Swiss-based operator. The action followed copyright-enforcement activity involving the MPAA and IFPI and removed one of the network's most important server hubs.

  Source

• 2006

  MetaMachine copyright settlement

  MetaMachine agreed to pay $30 million to avoid potential copyright-infringement lawsuits brought by the RIAA. It also agreed to stop distributing eDonkey software and to take measures intended to prevent file sharing through existing copies.

  Source

• Server poisoning and impersonation

  Some servers were reported to manipulate search results, censor content by file type or keyword, advertise fake files, or exaggerate user counts. Copyright-enforcement groups were also reported to have operated imitation Razorback2 servers that returned no useful results. These practices undermined search reliability and made user-count estimates difficult to interpret.

  Source

Read more

• 2006

  End distribution of eDonkey softwareOther

  Background

  MetaMachine faced potential copyright-infringement litigation from the RIAA over the use of its client for unauthorized sharing.

  Action taken

  MetaMachine agreed to a $30 million settlement, discontinued software distribution, and agreed to measures aimed at limiting use of existing copies.

  Aftermath

  The original eDonkey2000 client ceased to be maintained, while eMule and other compatible clients continued the broader protocol ecosystem.

  Settlement payment. $30 million (2006 settlement)

  Source

• 2002

  Shift toward Lugdunum-derived server softwareStrategy

  Background

  MetaMachine stopped actively maintaining its original server implementation, while reverse-engineered alternatives were being developed.

  Action taken

  Lugdunum-derived software extended the protocol while preserving compatibility and later became the basis for most active eDonkey servers.

  Aftermath

  The network gained a widely used alternative server implementation, although the software remained closed source and unofficially specified.

  Source

• 2000

  Launch a server-assisted peer-to-peer networkProduct launch

  Background

  The creators sought to support large files and continued availability without placing shared content in a central repository.

  Action taken

  The network used servers for search and source coordination while transferring files directly between participating clients.

  Aftermath

  This hybrid architecture enabled scale but left the network exposed to server congestion, server seizures, and dependence on frequently changing server lists.

  Source

• Develop distributed successors to server-based discoveryGeneration change

  Background

  Central server dependence created traffic bottlenecks and made the network vulnerable to disruption and legal intervention.

  Action taken

  MetaMachine developed Overnet, while the eMule project developed the Kad network and client-side source exchange.

  Aftermath

  The ecosystem gained more distributed discovery and transfer options, reducing reliance on individual eDonkey servers.

  Source

1. 1EDonkey networken.wikipedia.org