The peer-to-peer file-sharing service created by Shawn Fanning in 1999 was Napster.
Napster launched on June 1, 1999, after programmer Shawn Fanning developed the service with Sean Parker. It let users search a centralized index of music files while transferring the actual MP3 files directly between participating computers. That combination made music discovery and sharing dramatically easier than earlier, more cumbersome file-transfer systems.
The service spread rapidly through college communities and became a defining example of peer-to-peer networking. Its popularity also triggered major copyright litigation, including a lawsuit by the heavy-metal band Metallica and a case brought by the Recording Industry Association of America. Courts ultimately ordered Napster to block unauthorized sharing, and the original service shut down in 2001.
Napster is often confused with BitTorrent, but the technologies differ. Napster used a centralized directory to help users find files; BitTorrent, introduced later, distributes file metadata and sharing across a swarm. Napster’s collapse nevertheless helped accelerate the development of legitimate digital-music stores and subscription services.