This article discusses how to develop Twilio apps using ASP.NET MVC 4 Web API, focusing on leveraging the new WebApi features for building REST-like APIs that integrate with Twilio's Platform. The author provides a step-by-step guide on setting up the infrastructure for WebApi, adding UriPathExtensionMappings for XML and JSON formats, and creating a fictitious example of a Weather WebApi controller using the TwilioResponse object to serialize and send back XML payloads to Twilio. The article also covers testing locally with Curl utility and cross-referencing with Twilio's TwiML documentation, as well as exploring the use of Windows Azure Service Bus for relaying features in local development environments.