Voxeo announces that the Tropo.com cloud telephony service source code will be made available to developers for free under open-source licenses. The new Tropo source release demonstrates that cloud computing vendors can subscribe fully to open-source ideals, and avoid the proprietary lock-in typically found in cloud services. Tropo is the first of several new open-source projects from Voxeo Labs, the innovation and open-source focused organization announced by Voxeo yesterday at OSCON.

Tropo.com provides a cloud telephony service that enables developers to write voice applications in popular programming languages including Groovy, JavaScript, PHP, Python and Ruby. This approach stands in contrast to XML-centered options that have historically been the only option for cloud telephony services. Tropo applications can be written comfortably and directly in supported languages, with no need for inefficient intermediary translation to and from XML formats. Applications built on Tropo can answer and place calls via traditional landline phones, mobile phones, corporate PBXs and newer IP-based solutions such as SIP and Skype. In addition to being open-source, the Tropo platform is built entirely on open standards including SIP, Java SIP Servlets, and the IETF's Media Resource Control Protocol.

The Tropo source code released today includes:

• Tropo SIP Servlet, which implements the Tropo core Java API for telephony applications and a mechanism to host a wide variety of programming languages on top of that API. The Tropo SIP Servlet is built on the Java SIP Servlet standard, JSR-289. SIP Servlet platforms are available from many vendors including Voxeo, Oracle, Avaya, and Redhat. The Tropo SIP Servlet uses another standard, the IETF's MRCP standard to control audio interaction during calls. By open-sourcing this technology, Voxeo hopes to support a wider variety of MRCP servers, and ultimately support any media platform that implements the Java Media Server Control API, JSR-309.
• Tropo "Shims" for Groovy, JavaScript, Python, and Ruby programming languages. Tropo Shims adapt the Tropo core API for use in a specific programming language. Open-sourcing these components enables Tropo to quickly support other programming languages. By releasing this code and working with the open-source telephony community, Voxeo hopes to add support for additional programming languages such as Clojure, JavaFX, and Scala.

Over the coming weeks, Voxeo Labs will release additional Tropo components that will allow developers to run their own Tropo applications in private clouds, elastic computing services, or their own servers in conjunction with Voxeo's free Prophecy platform. Over the coming months, Voxeo Labs will work to support the widest variety of SIP Servlet and media server platforms, giving telephony application developers a simple yet powerful telephony API that works across the widest variety of platforms and vendors.

The Tropo platform source code is hosted on Github and is available immediately. Voxeo invites the developer community to join in building an open cloud telephony platform at http://labs.voxeo.com/tropo