Skype is a software application by Microsoft that allows users to make voice and video calls over the Internet. It features a Desktop API for external control.
Skype allows for free calls to other users within the same service, while calls to both traditional landline telephones and mobile phone can be made for a fee using a debit-based user account system. Skype has also become popular for its additional features which include instant messaging, file transfer, and video conferencing.
The network is operated by Skype Limited, which has its headquarters in Luxembourg, is minority owned by eBay and was acquired in 2011 by Microsoft. Most of the development team of Skype is situated in Tallinn, Estonia for cost reasons and outsourced by the Luxembourg parent company.
Unlike other VoIP services, the Skype company does not run only on servers, but makes use of background processing on computers running Skype software; the original name proposed—Sky peer-to-peer (see below)—reflects this.
Some network administrators have banned Skype on corporate, government, home, and education networks, citing reasons such as inappropriate usage of resources, excessive bandwidth usage, and security concerns.
