title: Building VOIP into an application (C++ specifically)
body: <p>Are there existing libraries and frameworks which allow VOIP to be built into a bespoke application without reinventing the wheel? A customer is interested by the possibility for a C++ desktop application and while it's not <em>hugely</em> useful (they could just use skype), it is quite <em>cool</em>.</p>
  
  <p>I believe some technologies like DirectX may have some functionality built in for in-game chat, is that right? What else is there in the form of free/paid 3rd-party libraries?</p>