tSIP - tomeko.net/software: SIP client for Windows.
Aavaz.biz - Aavaz Telemarketing Software is created to serve small businesses design and launch efficient calling campaigns, free from the traditional barriers of expensive and technological complexity.
PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).
Aheeva - The Omnibrand, Omnichannel, Omnilocation Contact Center Solution
Jami - Application and Data, Collaboration, and Web and Video Conferencing
EasyCall Cloud - EasyCall is call center system software easy and intuitive, the fully managed cloud solution for inbound and outbound calls of your contact and call center.