Blink is a fully featured and easy to use SIP client. Blink offers Rich Multimedia Communications based on SIP protocol using Future Proof Addressing in the form of an E-mail Address. Easy Integration with existing SIP Service Providers. Open Source, you get the source code and you can contribute.
FeaturesBlink implements RTP audio sessions (VoIP), session based Instant Messaging (IM), file transfer and multi-party chat sessions using MSRP protocol and its relay extension, desktop sharing using VNC protocol, publication and subscription for rich presence information, management for the presence rules, resource lists and RLS services documents using XCAP protocol.
To download the software go to http://iCanBlink.com