Billion Phone - compact convenient SIP phone software for making voice calls.
Enables voice connections to landline , cellular network and VoIP.
SIP Communicator - the Java VoIP and Instant Messaging client.
VoIP SIP SDK provides a powerful and highly customizable solution.
Net2Phone SIP Dialer lets you make phone calls using your computer.
Configure SIP accounts, perform VoIP phone calls or initiate audio conferences.
Myvoipapp Sip Phone is a usefull tolls easy to use.
A free SIP Softphone which offers PC-to-Phone service.
New generation phone system working in IP-networks using SIP protocol.
It enables you to make voice and video phone calls using SIP-based standards.
PortSIP Solutions, Inc.
PortGo Professional is a SIP-based phone for Windows desktop.
Frankcall provide PC to Phone, Mobile VOIP, Mobile SIP, Mobile Dialer services.
Nimbuzz - Call
Nimbuzz Phone is company's utility SIP caller for windows platform.