Lesson 2, Platform as a Service. Platform as a Service delivers standard and top-of-the-line development frameworks and tools. Firms of any size can implement development environments that match their needs, and there is no need, again, for big investments in the IT infrastructure to support these development environments. These development environments can come prepackaged with certain offerings. They can include the latest and best tools for application development maintenance. A big offering with Platform as a Service is a DevOps tool offering. DevOps is an Agile methodology, and quite often, it's implemented by suites of tools. Suites of tools do require configuration, maintenance, upgrades, which can equate to a lot of overhead. Therefore, when offered by Platform as a Service, it often is more efficient for firms who are developing applications. And as we can see here, this data center, a remote data center, is offering the DevOps and the other cloud computing services to the customer firms, and they're able to take advantage on, again, a subscription basis. And Platform as a Service offers the advantages of lower costs, quite often expertise. As we can see here, some of these developer apps may require some level of expertise, and very often the cloud providers provide the expertise on demand. Multiple operating systems development, as well. So if a firm wants to support many development operating systems, which is often the case today, with mobile, these operating systems are easily delivered at through Platform as a Service. Quite often, the model is pay-as-you-go or rental, and it can often include very sophisticated development environments. Platform as a Service enables geographic round-the-clock development as well for the same type of investment, and the use of an out-of-the-box application development lifecycle and tools can also be included as the pay-as-you-go model. That refers back to the DevOps suite of tools. And also, releasing of applications onto the infrastructure as a service. So the Platform as a Service gives us the environments to build the applications, but also the tools and environments to release to virtual runtime environments, which most likely would be included in the Infrastructure as a Service. And some examples of Platform as a Service include Amazon Web Services, Elastic Beanstalk, Microsoft Azure, Heroku, Force.com, Google App Engine, and Apache Stratos.