E-goi - Email Marketing companies, SMS Marketing, software email marketing.
Asterisk - An open source telephony switching and private branch exchange service for Linux.
Octopush - Octopush is a company providing technology-based communication solutions, including SMS, Web solutions, and Email APIs.
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.
Maytapi - Serverless Whatsapp Api with Chat and Agent support.
FusionPBX - FusionPBX is an open source FreeSWITCH GUI.