Skype is a software program created by the entrepreneurs Niklas Zennström and Janus Friis. Skype allows users to make telephone calls from their computer to other Skype users free of charge, or to landlines and cell phones for a fee. Additional features include instant messaging, file transfer, short message service, video conferencing and its ability to circumvent firewalls.

The Skype Group, acquired by eBay in September 2005, has headquarters in Luxembourg, with offices in London, Tallinn, Tartu, Prague and San Jose, California. Skype has experienced rapid growth in both popular usage and software development since launch, both of its free and its paid services.