It is similar to the CGI feature of web servers in allowing any language to be used for writing the external program which communicates with Asterisk via stdin and stdout.
interface | Graphical user interface | Gateway | graphical user interface | User interface | Gateway Arch | Asterisk | Application programming interface | User interface design | user interface | Gateway of India | Common Gateway Interface | Gateway Region | application programming interface | Thames Gateway | Serial Peripheral Interface Bus | Media gateway | Graphics Device Interface | Gateway Center | gateway | Application Programming Interface | Web Server Gateway Interface | Intelligent Platform Management Interface | Gateway (telecommunications) | Enbridge Northern Gateway Pipelines | Command-line interface | command-line interface | Basic Rate Interface | Analog Display Services Interface | XML User Interface |