RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Asterisk - An open source telephony switching and private branch exchange service for Linux.
Nextiva - Business VoIP, cloud phone systems trusted by more than 150,000 companies. Powered by the leading cloud PBX VoIP platform, Nextiva is rated the best business VoIP service provider.
FreeSWITCH - FreeSWITCH is an open-source media application designed to support popular protools such as SIP and WebRTC and provides a platform to develop voice and video applications.
Unify Office by RingCentral - Unify Office is the new cloud team collaboration and communications service delivered by Atos Unify in partnership with RingCentral, a market leader in UCaaS.
Kamailio - Kamailio® (successor of former OpenSER and SER) is an open source SIP server released under...