Multimodal Browser Extension is a technology that enables Microsoft Internet Explorer to render multimodal applications written according to the W3C Acknowledged Submission, XHTML+Voice (X+V). This technology, which includes IBM's automatic speech recognition and text-to-speech engines, allows testing of voice-enabled Web applications written in the X+V language.

After installing the extension, multimodal applications can be opened in Internet Explorer. For voice-enabled fields, the Scroll Lock key can be used as the Push-to-Talk button. The browser can be used as a simulator and the application can be tested from the "end user" perspective to resolve any remaining problems before deployment. Multimodal Browser Extension is a plug-in for Internet Explorer 5.5 or above on a Windows 2000 or XP platform.