Peer-to-peer communication software with the capability to make and receive audio and video calls to other Skype clients (for free) and land lines for low cost. Additionally it supports instant messaging, chat rooms, audio & video conferencing, file transfers, text (SMS) messaging and voicemail.
In the second week of August 2014 Microsoft finally disabled logins from old versions of Skype. In order to use the Windows version of Skype you have to run version 6.14 or higher.
Submitted test data from old Skype versions will be dismissed.
Skype 4.0 introduced a completely overhauled UI. Now by default all Skype conversations take place in the central window. Turning Skype from an small accessory to an app that requires nearly full screen.