How is OpenVBX different from Twilio?
OpenVBX is an open source project started by Twilio that is powered by Twilio’s hosted phone and SMS service. In order to make and receive phone calls using OpenVBX, you must have a Twilio.com account. OpenVBX extends Twilio’s API by providing a user interface and other primitives like voicemail that build upon Twilio’s core API stack. OpenVBX is designed to be extensible by developers, and ease to use by end users.