Skype originally featured a hybrid peer-to-peer and client–server system. As of 2011, most of the development team and 44% of all the division's employees were in Tallinn and Tartu, Estonia. In May 2011, Microsoft bought Skype for $8.5 billion and used it to replace their Windows Live Messenger. In September 2009, Silver Lake, Andreessen Horowitz, and the Canada Pension Plan Investment Board bought 65% of Skype for $1.9 billion from eBay, valuing the business at $2.92 billion.

In September 2005, eBay acquired Skype for $2.6 billion.

Skype was created by Niklas Zennström, Janus Friis, and four Estonian developers and first released in August 2003. Skype is available on various desktop, mobile, and video game console platforms. It also has instant messaging, file transfer, debit-based calls to landline and mobile telephones (over traditional telephone networks), and other features. Skype ( / s k aɪ p/) is a proprietary telecommunications application operated by Skype Technologies, a division of Microsoft, best known for VoIP-based videotelephony, videoconferencing and voice calls. Videoconferencing, VoIP and Instant messaging Windows, macOS, Linux, Android, iOS, iPadOS, HoloLens, Xbox One, Xbox Series X/S

System requirements for skype 8.