A voice browser is a web browser that presents an interactive voice user interface to the user. In addition, it typically provides an interface to the PSTN or a PBX. Just as a visual web browser works with HTML pages, a voice browser operates on pages that specify voice dialogues. Typically these pages are written in VoiceXML, the W3C's standard voice dialog markup language, but other proprietary voice dialogue languages remain in use.
A voice browser presents information aurally, using pre-recorded audio file playback or using text-to-speech software to render textual information as audio. A voice browser obtains information using speech recognition and keypad entry (e.g., DTMF detection).
As speech recognition and web technologies have matured over the past decade, thousands of voice applications have been deployed commercially and voice browsers are supplanting traditional proprietary IVR systems. Scores of companies provide voice browsers. These take the form of software, packaged hardware/software solutions or hosted solutions.
See also 
- CCXML - Call Control eXtensible Markup Language
- VoiceXML - Voice Dialog eXtensible Markup Language
- SRGS - Speech Recognition Grammar Specification
- SISR - Semantic Interpretation for Speech Recognition
- SSML - Speech Synthesis Markup Language
- PLS - Pronunciation Lexicon Specification
- ECMAScript - Scripting language supported by most voice browsers
- W3C's list of VoiceXML browsers
- Ken Rehor's VoiceXML platform list
- VoiceXML Forum
- W3C Voice Browser Working Group
- VXI* Voice Browser for Asterisk PBX
- VoiceXML Development Guide
- Voice Browsing IE Toolbar by Yan Michalevsky
- Project metalmouth - Developing an open source voice browser extension for Chrome