Skype

Skype ( /ˈskaɪp/) is a software application that allows users to make voice and video calls and chats over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones 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 videoconferencing. Skype has 663 million registered users as of September 2011.[1] The network is operated by Skype Limited, which has its headquarters in Luxembourg. Most of the development team and 44% of the overall employees of Skype are situated in the offices of Tallinn and Tartu, Estonia.[2][3]
Unlike other VoIP services, Skype is a peer-to-peer system rather than a client–server system, and makes use of background processing on computers running Skype software; the original name proposed – Sky peer-to-peer – reflects this.
Some network administrators have banned Skype on corporate,[4] government, home, and education networks,[5] citing reasons such as inappropriate usage of resources, excessive bandwidth usage,[6] and security concerns.[7]
On 10 May 2011, Microsoft Corporation agreed to acquire Skype Communications, S.à r.l for US$8.5 billion.[8] The company is to be incorporated as a division of Microsoft, and Microsoft will acquire all of the company's technologies, including Skype, with the purchase.[8]

Download Homepage:
http://www.skype.com/intl/en/welcomeback/