Plivo is an open core SMS API and Voice API platform that enables businesses to communicate with their customers on a global scale. Plivo's enterprise-grade communications platform includes a premium carrier network with connectivity in 190+ countries, an API platform for messaging and voice calls, and solutions for sales/ support teams.
Fonos is an open-source alternative to Twilio. Fonos aims to solve businesses needing to add voice, video, and messaging features to their websites and applications. Companies are, in most cases, unable to accomplish this independently due to the complexity and number of telephony services involved in the task.