Skype, it is a proprietary telecommunication application that specialises in delivering VoIP-based services such as videotelephony, videoconferencing, and voice conversations. There are a variety of other features such as instant messaging, data transfer, debit-based calls to landlines and mobile phones (through conventional telephone networks), and more. In addition to desktop, mobile, and video game console platforms, Skype is also accessible on the Xbox 360 and PlayStation 3. Skype Technologies, a Microsoft subsidiary, is responsible for the service's development and operation. Currently, Skype is utilised by over 100 million people on a monthly basis, with 40 million people using it every day as of March of this year.
A collaboration between Niklas Zennström and Janus Friis, as well as the help of four Estonian engineers, Skype was first made public in August 2003. A total of $2.6 billion was paid by eBay for the acquisition of Skype in September of that year. Skype was acquired by eBay for $1.9 billion in September 2009, with Silver Lake, Andreessen Horowitz, and the Canada Pension Plan Investment Board announcing the deal. The business had a market value of $2.92 billion at the time of the purchase. With the purchase of Skype by Microsoft in May 2011, the company replaced its Windows Live Messenger service with it. Tallinn and Tartu, Estonia continue to be the home base for majority of the development team and 44 percent of the whole division's workforce as of 2011.
When Skype was launched, it used a hybrid peer-to-peer and client–server architecture to facilitate communication. Skype became fully powered by Microsoft-operated supercomputers in May 2012 and switched from being a peer-to-peer service to being a centralised Azure-based service in January of this year.