lightweight SIP softphone
MicroSIP allows you to make high quality VoIP calls via open SIP protocol. You can select the best SIP provider for you. You'll get free person-to-person calls and cheap international calls. MicroSIP has an easy to use interface, support for all major voice codecs, support for SIP functionality (voice, messaging, presence, video h264 and h263+) and privacy (configurable encryption TLS / SRTP for control and media).