HVP is a high-density telephony call control and media processing platform, used to build voice applications. The platform provides native call control & media handling APIs, as well as supporting a VoiceXML interpreter & (a subset of) CCXML. HVP's features allow mobile users to share voice messages and data regardless of the network and handset technology. It allows for applications to interact with the user in the "Early Media" phase of the call, thereby, supporting advanced messaging.