Kazaa Media Desktop (once stylized as "KaZaA", but now usually written "Kazaa") started as a peer-to-peer file sharing application using the FastTrack protocol licensed by Joltid Ltd. and operated as Kazaa by Sharman Networks. Kazaa was subsequently under license as a legal music subscription service by Atrinsic, Inc. As of August 2012, the Kazaa website is no longer active.
Kazaa Media Desktop was commonly used to exchange MP3 music files and other file types, such as videos, applications, and documents over the internet. The Kazaa Media Desktop client could be downloaded free of charge; however, it was bundled with adware and for a period there were "No spyware" warnings found on Kazaa's website. During the past few years, Sharman Networks and its business partners and associates were the target of copyright-related lawsuits, related to the copyright of content distributed via Kazaa Media Desktop on the FastTrack protocol.
Read more about Kazaa: History, Lawsuits, Bundled Malware, Transitional Period, Variations