Integration and collaboration are important needs for software to achieve business processes. Old and modern software applications run on multiple kinds of IT platforms and infrastructures. Software solutions automate most business processes. However, business applications have to spontaneously synchronize with other software packages in order to bear fruit. Processes, applications, and data have to be integrated to guarantee a comprehensive yet compact view for executives and end users. Communication is the key. APIs are the widely-recognized mechanism for software components to find one another to interact with in a systematic manner. APIs are being created and supplied with any kind of software, including web and cloud applications, databases, middleware, and platforms. The current internet paradigm is steadily expanding. Once upon a time, the internet was the network of networked computers. That is, all kinds of computers (both clients and servers) were networked to share their unique capabilities.

These days, not only computers but also our communicators and consumer electronics, such as smartphones, personal digital assistants (PDAs), tablets, laptops, handhelds, and communication gateways, are also joining the internet. Precisely speaking, the internet of devices (IoD) paradigm is fast emerging and evolving.

All kinds of personal and professional devices, instruments, appliances, and machines are getting connected to the internet; all kinds of common and cheap things in our everyday environments are getting digitized with the help of scores of digitization and edge technologies and tools in order to be sufficiently empowered to join mainstream computing. Everyday items are becoming computational, communicative, sensitive, responsive, and active with the appropriate enablement of powerful and pioneering technologies. Now, with the faster stability of service-engineering techniques, we see the world as the Internet of Services (IoS). That is, everything is expressed and exposed as a service for the outside world. All kinds of software and hardware systems, including embedded systems, are being presented as a collection of publicly-addressable and-available services. This is ultimately helping to hide systems' complexities and deficiencies.

At one end, we see an increased number of hardware systems (IT infrastructures), software applications and services, data sources, and scores of platforms in the internet space. However, creating and sustaining APIs for these kinds of internet-attached systems, applications, and services isn't an easy task. At the other end, we have a variety of digitized, embedded, networked, handy, trendy, slim, and sleek I/O devices. Hence, in order to establish a beneficial link between the ground-level systems and the faraway internet-hosted systems, APIs are the way forward. In short, the RESTful service paradigm comes as a solace by simplifying and streamlining API creation and usage for systems integration and collaboration.