The Twilio Ruby Helper Library is a gem that allows Ruby developers to issue requests to the Twilio API and generate TwiML. Quickstart tutorials are available to help developers get started with the library.
#blue is a web service to save text messages in an intelligent, searchable manner. It's a service of O2 UK, and sadly only currently available to O2 UK subscribers. However, it's a rather interesting web service, and it'd be great to see more service providers use a similar service. The fully functional #blue API provides a compliment to its web based service.
In theory the rise of software-defined networking is supposed to give rise to a new class of applications that will give developers more control over, for example, location-based services. In actual practice no one is quite certain how developer will invoke SDN capabilities, but the folks at Hewlett-Packard are anxious to find out.