<p>Fast and accurate speech recognition systems bring with them the possibility <br>of designing flexible voice driven applications. In this paper, we highlight <br>the needs related to a voice interface and describe the implementation of <br>a general-purpose spoken language interface, the Camegie Mellon Spoken <br>Language Shell (CM-SLS). CM-SLS provides voice interface services to <br>different applications running on the same computer. CM-SLS was used <br>to build the Office Manager, a collection of applications that includes an <br>appointment calendar, a personal database, voice mail and a calculator. The <br>performance of several system components is described.</p>