Wikipedia
Nasza-klasa.pl
NK.pl, formerly Nasza-klasa.pl (nasza klasa is Polish for "our class"), is a large Polish school-based social networking service used by alumni and students. NK.pl is owned 70% owned by Forticom and the rest is owned by the Polish Nasza-Klasa Sp.z.o.o., Nasza-Klasa's founding company.