From what used to be a purely technical concept created to make developers' lives easier, Application Programming Interfaces (APIs) have evolved into one of the foundations of modern digital business. Today, APIs can be found everywhere -- at homes and in mobile devices, in corporate networks and in the cloud, even in industrial environments, to say nothing about the Internet of Things. 

As companies are struggling to maintain their business agility, to react to the ever-changing market demands and technology landscapes, the need to deliver a new application or service to customers as quickly as possible often trumps all other considerations. Rapidly growing demand for exposing and consuming APIs, which enables organizations to create new business models and connect with partners and customers, has tipped the industry towards adopting lightweight RESTful APIs, which are commonly used today.