Linphone is an internet phone or Voice Over IP phone (VoIP). * With linphone you can communicate freely with people over the internet, with voice, video, and text instant messaging * Linphone makes use of the SIP protocol, an open standard for internet telephony. You can use Linphone with any SIP VoIP operator, including the free SIP audio/video service provided by www.linphone.org * Linphone is available for desktop computers: Linux, Windows, MacOSX, and for mobile phones: Android, iPhone, Blackberry