NK.pl
NK.pl, formerly Nasza-klasa.pl (English: Our-class.pl), was a Polish school-based social networking service used by alumni and students. NK.pl was owned and administered by Ringier Axel Springer Polska. History NK.pl was launched on 11 November 2006 by Maciej Popowicz, Paweł Olchawa, Michał Bartoszkiewicz, and Łukasz Adziński, four college students studying computer science at the University of Wrocław. The company was headquartered in Wrocław, Poland, and its name came from the song "Nasza Klasa" by Jacek Kaczmarski. The website enjoyed success, and one 2009 study called it a "model example of the ‘rags to riches’ ideal of an enterprise construed with no financial funding and no institutional support (neither from ASP/ISP corporations nor from central/local administration)". In 2009, the service had 13.5 million active users. NK.pl then ranked among the top five websites used in Poland, behind Google.pl, Onet.pl, and Wirtualna Polska, and it was visited by more than 50% of Polish Internet users each month (with 10% of the traffic coming from abroad). As of July 2009 86% of its users lived in Poland, according to Alexa. The site was also popular in Norway, where it was the fifth most popular social networking website in 2009. In June 2010, a rebranding