<p>Asterisk is the world's leading open-source PBX, telephony engine, and telephony applications toolkit with immense flexibility.<br /><br />This book will give you a firm understanding of Asterisk Gateway Interface (AGI) development and proper AGI development practices. You will learn how to formulate Atomic AGI-enabled scripts, enabling rapid development within a well-defined Asterisk execution and runtime environment.<br /><br />This book builds from the simplest form of an Asterisk application, the dialplan-based application, gradually building a full understanding of AGI scripting. The book also introduces a new concept of AGI development named "Atomic AGI" or "Particle Programming". It will introduce you to various techniques of interacting with the user, where user interaction isn't limited to keypad-based input, but also includes recording messages from the user, sending output to the user, and controlling the call flow.<br /><br />The book takes a pragmatic approach with clear and complete examples, and a service development project &acirc;&euro;&rdquo; allowing you to understand the project cycle of developing an Asterisk-based service or application.</p>