UniXcape is an internet phone (VoIP), compatible with the SIP protocol.
If you subscribe a VoIP to PSTN (=classic telephony) account to a telecom provider, you can reach everyone that has a "classic" phone line. Alternatively.
UniXcape available on UniXcape mobility only.
List of supported features: -Audio with the following codecs: Speex8 -Vdeo with the following codecs: H264 -Chat message -multiple calls -audio conferencing -Address book integration -Call history -DTMF (telephone tones) support using SIP INFO or RFC2833