NEW YORK - Voxeo Corporation and DemandVoice entered an agreement under which Voxeo will supply DemandVoice with an OEM version of Evolution Designer, a graphical development tool for VoiceXML and VoIP-based telephony applications. When the new system goes live later this month, DemandVoice customers will be able to build applications using a Web-based interface then deploy them to DemandVoice production servers.  Evolution Designer also enables customers to manage multiple applications through the same Web interface.