VoiceXML has been developed as a markup language in conjunction with speech recognition for navigation using speech. It consists of several components, including a telephone network, IP network, telephony server, web server and a database. However, VoiceXML can also be used in conjunction with speech synthesis for synthetic speech output of content.
VoiceXML was specified by the W3C consortium and provides developers and service providers with a programming interface for XML applications for voice and telephony resources. VoiceXML is used in speech browsers, virtual agents and chatbots.