The Twilio helper libraries are available on NuGet, Microsoft's open-source package management system, allowing .NET developers to easily add them to their projects without leaving Visual Studio or WebMatrix. These libraries simplify using the Twilio REST API and provide utilities for working with TwiML and Twilio Client. Adding these libraries can be done through Visual Studio 2010 by searching for "Twilio" in the NuGet catalog, clicking the Install button, and watching as NuGet downloads and adds the references to the project. For WebMatrix users, the process is similar, but involves opening the WebMatrix administration website, changing the Show dropdown to Online, searching for Twilio, and clicking the Install button. With these libraries added, developers can make requests to the Twilio REST API using the Twilio.API library, as covered in the next post.