Skype was founded in 2003 by the Swedish entrepreneur Niklas Zennström and Dane Janus Friis. The Skype software was developed by Estonian developers Ahti Heinla, Priit Kasesalu and Jaan Tallinn, the same individuals who together with Niklas and Janus were also originally behind the peer-to-peer file sharing software Kazaa. In April 2003, Skype.com and Skype.net domain names were registered. In August 2003, the first public beta version was released.