The questions have been there for years: Why not send a text message to your airline rather than waiting on hold for an hour? Why can’t my customer information be passed up the call chain with the same ease as my voice? Where are all the cool VoIP applications?

VoIP (voice over IP) has been a buzzword since the turn of the millennium. Now, through the rise of the cloud, VoIP is entering the era of the API. Companies like 2600hz, One Source Networks and Twilio are breaking down the barriers between enterprise phone systems and enterprise applications.

Jeff Lawson, founder and CEO of Twilio, said that VoIP hasn’t been a first-class Web citizen until recently. “It’s not something that was accessible to most developers. It was esoteric and in a totally different realm of programming and technology. Telecom is nothing new, but making it accessible to those Web developers is,” he said.

To that end, Twilio built its cloud-based VoIP APIs with the intention of making the services useful and comprehensible to Web developers. And that, said Lawson, is the key to spreading VoIP integrations.

“We’ve always been about the Web developer,” he said. “It’s the perspective we came from. Before Twilio, I was not in telecom; I was in Web development. We wanted to make these technologies first-class citizens of the Internet. We offer RESTful APIs, and it’s Web technology: HTTP, XML, and you can use it with PHP, Python, or other popular Web languages.”

Gina Nomellini, chief marketing officer at One Source Networks, said that APIs have become the lifeblood of VoIP. “[One Source] sees a number of API interface requirements from its enterprise customer base,” she said. “Our clients have requested to interface with APIs from our hosted VoIP services to Salesforce automation tools such as and Microsoft Dynamics, as well as integration with [Microsoft] Outlook.”

For many companies, adding VoIP integrations to enterprise applications can offer a more diverse way for employees to interact with one another and with customers, said Nomellini. “By leveraging this technology, enterprises achieve flexibility and cost savings, as well as the feature-rich services that a VoIP platform enables,” she said.

“VoIP provides companies with the ability for increased collaboration. It integrates an employee’s entire workstation from their computer to the telephone, allowing them to be more efficient and increase productivity. Today’s VoIP solutions leverage a user’s e-mail, chat features, voice, messaging and video capabilities to provide a holistic service that enhances an enterprise’s ability to respond to its customers more efficiently.”