Plivo provides a telephony application development framework that allows developers to build applications using telephony building blocks through RESTful APIs and XML. It can be used to create applications like click-to-call systems, PBXs, IVRs, voice-mail systems and more. Plivo handles the connection to the telephony network and developers can focus on their custom application logic. The framework has been tested to handle up to 2000 concurrent calls and can scale horizontally across instances.