sip softphone

SIP Communicator - the Java VoIP and Instant Messaging client.

SIP Express Router (SER) is a high-performance, configurable

Softphone will let you call online frinds for free.

Net-SIP will implements all SIP protocol operation using EventMachine network.

Avaya IP Softphone

Easy to use Free SIP Softphone for voip providers

Softphone for PC-telephony using TAPI, CAPI or SIP plus answering machine

Free Softphone for Windows. Works with any SIP/ VOIP provider and SIP PBX

TekSIP is a SIP Registrar and Stateless SIP Proxy for Windows.

TekSIP is a SIP Registrar and Stateless SIP Proxy for Windows.