Twilio - Brings voice and messaging to your web and mobile applications.
irssi - Irssi is a terminal based IRC client for UNIX systems.
Plivo - Plivo simplifies your customer engagement.
LimeChat - LimeChat is an IRC client for Windows, Mac OS X and iOS. Features
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
WeeChat - WeeChat is a fast, light and extensible chat client.