Ozeki SDK v1.9.12
Ozeki VoIP SIP SDK provides a first-rate technology for softphone development. Instead of wasting time for long development process on your own, you can take advantage on this decent software development kit. You will see how easy it is to create a softphone when you use Ozeki SIP SDK. A basic programming knowledge is enough, since Ozeki SIP SDK provides the base for the VoIP solution you are working on.