Pre-Napster: The Paleo-swapping years

Before there were modern peer-to-peer services, files were routinely traded through Internet Relay Chat (IRC) channels, Usenet newsgroups and FTP servers. MP3 sites such as Ministry of Sound and Mighty Mo's MP3s offered downloads from Web sites. A handful of early software applications, such as Scour Media Agent and Hotline offered rudimentary peer-to-peer capabilities.

Recording industry lawyers and other copyright authorities routinely targeted hubs of online copyright infringement, but the actions, taking place under the mainstream radar, drew little public attention.

Key names

IRC, FTP, Usenet, Blex's Page of Good MP3s

Key dates

Jun 1997 - RIAA filed lawsuits against three MP3 download site operators.
Oct 1998 - RIAA sued Diamond Multimedia over release of MP3 player.
Feb 1999 - Lycos released Web music search tool; RIAA threatened lawsuit.

First generation - Napster and the mainstream

Napster changed the music business in the space of months. Released as a beta program in the spring of 1999 by college student Shawn Fanning, it allowed millions of people to link their hard drives into a collective pool of downloadable free music.

Fanning's software and its immediate followers were based on a centralized technology, making them an easy target for record companies and other copyright holders. A central server kept track of all the songs stored on users' hard drives. Anyone who wanted a piece of music would query the Napster software, which would respond with available options, and then connect the user directly to the computer that had the song available for a download.

Most of these companies went offline or changed their business model after being sued by the RIAA.

Key names

Napster, Scour Exchange, Audio Galaxy, iMesh (original), Aimster

Key dates

Spring 1999 - Napster beta program released.
Dec 1999 - RIAA sued Napster.
Jul 2000 - RIAA sued Scour.
Jul 2000 - San Francisco federal court ordered Napster to stop music-swapping.
Feb 2001 - An appeals court upheld Napster order; company started blocking swaps soon afterward.

Second generation - Decentralization and legal reversals

Repeated lawsuits and technological glitches highlighted weaknesses in Napster's centralized model. In response, a new generation of developers created networks without Napster's central servers.

Under this new model, a first computer would connect to another in the network, and ask it for a file. That second computer would ask a third, which would in turn ask a fourth, and so on until the file was found. The last computer in line would then connect directly to the first for a download. More sophisticated versions later streamlined this process, by allowing some computers to store information about nearby machines.

These decentralized models made the networks stronger, because--in theory--they could survive the failure of their parent company. They also provided some legal shield, because companies could argue that they had no direct control over or knowledge of illegal activity on the networks.

Key names

Gnutella (including LimeWire, Bearshare, and later Morpheus), Kazaa, Grokster

Key dates

Mar 2000 - AOL subsidiary Nullsoft released Gnutella code online without corporate approval.
Oct 2001 - RIAA sued Kazaa, Grokster and MusicCity (now StreamCast Networks).
Feb 2002 - Millions of Morpheus users locked out of Kazaa's network overnight.
April 2003 - Los Angeles court ruled Grokster wasn't liable for users' copyright infringement.
Sep 2003 - RIAA filed first lawsuits against individual file-swappers.
Aug 2004 - Appeals court upheld Los Angeles Grokster ruling.
Jun 2005 - Supreme Court ruled on Grokster's legality.

Today's swappers: Torrents of video

Driven by faster Net connections and other technological advances, swappers are increasingly trading movies, software and games online. File-swapping tools are adapting in turn.

Most recent developments have focused on improving the efficiency of large file downloads and expanding search features, while retaining a decentralized model. Some networks have sought to improve privacy, but without reaching perfect anonymity.

By this time, no single network dominates as Napster did in the first generation and Kazaa did through much of the second generation. Millions of people can be found on swapping networks at any given hour of the day, with people using different tools for different kinds of content.

Key names

BitTorrent, eDonkey/eMule, Exeem

Key dates

Feb 2002 - Bram Cohen released BitTorrent at CodeCon 2002.
Jul 2004 - BitTorrent swaps accounted for 53 percent of all Internet traffic, company said.
Oct 2004 - eDonkey passed Kazaa as top file-swapping network.
Dec 2004 - MPAA began legal attack on BitTorrent hubs.