Cloud-based infrastructure as a service (IaaS) is for renting storage and compute capacity from a service provider, delivered via an Internet connection. Similarly, software as a service (SaaS) is for accessing applications that are hosted in the cloud.
Platform as a service (PaaS) is sort of the like the red-headed stepchild between the two, providing an application development and hosting platform in the cloud. PaaS in many ways combines elements of infrastructure and software as a service.
But recently, Gartner researcher John Rymer, who closely tracks the PaaS market, says the lines between IaaS, SaaS and PaaS are beginning to blur.
Some of the leading IaaS companies, like Amazon Web Services, are adding PaaS-like features to their offerings. AWS has made it easier to deploy and scale applications in its cloud through services like its recently released OpsWorks, as well as Elastic Beanstalk and CloudFront, for example. SaaS pioneer Salesforce.com, meanwhile, is making a big push to promote its integrated PaaS offerings, Force.com and Heroku.
IaaS and SaaS are still strong markets in their own right, but increasingly providers in these areas are migrating toward the PaaS market as well. "These models are getting a good amount of usage," Rymer says.
Rymer says the blurring of the lines between IaaS, SaaS and PaaS is driven by a couple of major factors. For one, vendors are looking to expand their service offerings to appeal to a wider customer base. Secondarily though, users are using the cloud in new ways, and looking for functionality from their providers. Rymer breaks PaaS users down into three buckets:
These are application developers who want an easy platform for developing applications without having to worry about configuring the infrastructure that the apps run on -- they just want to code in their programming language of choice -- Java, .Net, Ruby, Python, etc. A variety of pure-play PaaS vendors serve this market, including vendors like CloudBees, Engine Yard, Heroku and even Oracle, to an extent.
These are developers who like the idea of being able to build and deploy apps quickly, but they still want to have some control over the operations infrastructure, particularly for large-scale apps. "Usually when the apps get big, they want to tune the size of the VMs (virtual machines), storage and other components," he says. These are the ideal customers for IaaS providers looking to move up the stack into PaaS-like features.
These folks build applications, but they're not coders. These users are served well by tools offered from services like Force.com, which have intuitive visualization features, allowing users to build applications without coding in programming languages. Force.com is an example of a service that would allow this functionality.
Sign up for MIS Asia eNewsletters.