Models of PaaS
There are three models of cloud computing such as PaaS, SaaS, and laaS. While the Paas platform as a service provider, Saas works as software as a service, and finally laaS refers to the computing infrastructure that includes both servicing and storage. And this is managed by the cloud vendors and similarly SaaS is managed by the SaaS providers.
There are many examples of PaaS providers who can supply the tools and services needed to build the applications in the cloud. Some of them are: Google, Microsoft, Red hat, pivotal, oracle, heroku, Engine Yard, etc.
Out of this Google supports websites for the distributing applications such as Java, Python, PHP and Go. While the Red Hat is a PaaS offering for creating open source applications using a wide languages, databases and components. Microsoft Azure PaaS services supports application in terms of .NET, Node.js, etc. and thereby allows the developers to use software developer kits to create and deploy applications.
On the other hand, Aws PaaS service allows users to create, deploy and scale web applications and service developed with Java, .NET, PHP, Python, Ruby, Go and Docker on common, servers including Nginx, IIS, and Passenger.
Though many PaaS providers offers similar services, every provider has unique nuances and also certain limitations.