1. A method of processing a voice command spoken into a communication device, the method comprising: establishing a connection via a communication network between an application server and the communication device; receiving, by the application server, the voice command spoken into the communication device and communicated to the application server via said connection; accessing a web service stored on the application server; processing the voice command with the web service on the application server; determining, by a multimodal adapter of the application server, modality requirements for a multimodal application operating on the communication device, the modality requirements specifying characteristics of a modality web service capable of processing the voice command; selecting, by the multimodal adapter of the application server, the modality web service in dependence upon the modality requirements; and returning, from the application server to the communication device, a multimodal signal configured to render a user interface on the communication device.