Gips is expanding to domain of servers, clients from the core audio engine product.
The gips site says : REX PC is a comprehensive communication solution that leverages the Internet to deliver advanced features such as PC based calling, IM and voicemail. REX also provides the features and functions that service providers seek in a softphone. The customizable GUI allows service providers to deploy a softphone with the look and feel of their choice..
This ends up lot small scale developers.
web : http://www.gipscorp.com/rex/rex.html