Skype- Instant Messaging Tools

Developer(s)
Initial release	August 2003 (2003-08)
Stable release	5.5.0.115 (Windows) 5.3.0.1093 (Mac OS X) 3.0.1 (iOS) 2.2.0.35 (Linux) 2.1.0.46 (Android)  (1 September 2011; 10 days ago (2011-09-01) (Windows) 1 September 2011; 10 days ago (2011-09-01) (Mac OS X) 29 February 2011; 6 months ago (2011-02-29) (iOS) 2 June 2011; 3 months ago (2011-06-02) (Linux) 4 August 2011; 38 days ago (2011-08-04) (Android)) [+/−]
Preview release	5.5.1 [+/−]
Written in	Embarcadero Delphi, Objective-C (iOS, Mac OS X), C++ with Qt4 (Linux)
Operating system	Cross-platform
Available in	Multilingual
Type	Voice over Internet Protocol, instant messaging, videoconferencing
License	Proprietary, some paid features