Skype è un software proprietario freeware di messaggistica istantanea e VoIP. Esso unisce caratteristiche presenti nei client più comuni ad un sistema di telefonate basato su un network Peer-to-peer.
Unified communications plan that includes enterprise Instant Messaging, Presence and pc-to-pc audio and video calling capabilities.
Unified communications plan with advanced capabilities including enterprise Instant Messaging, Presence and online meetings with audio and video conferencing and multiparty data sharing.