IaaS (Infrastructure as a Service) and PaaS (Platform as a Service) are often described as competing paradigms for the future of the cloud.
A commonly heard view is “PaaS is the future of cloud services and IaaS will slowly go into the background”.
Here is a contrary view.
The real world is of course more interesting then that. IaaS platforms do offer PaaS solutions through their eco-system: Heroku (on AWS) is often mentioned; and Windows servers on AWS can of course run .NET…
Conversely, PaaS providers are bringing out IaaS-like features: Microsft Azure recently brought out the ability to create images of servers (IaaS has had this feature for some time) and has long offered “Azure Blobs” as a competitor to AWS S3; Google recently added “Google Storage” and is rumored to be cooking an EC2 competitor.
More fundamentally, it is a fact that the IaaS approach has attracted many new adopters to the market. One reason is: the nuts-and-bolts approach of IaaS makes it easy (or easier) to port existing applications to the cloud, quickly.
This benefit is not going away, any time soon. It may well be the reason Microsoft and Google are adding IaaS-like features.
What will the future bring? Gazing in our crystal ball, we see the clouds becoming brighter
Most major vendors will offer a layered stack: a lower IaaS layer directly exposed through Web Service APIs, and a PaaS layer running on top of the IaaS layer.
The PaaS layer will expose one or more programming models (Ruby, Python, Java, .NET, …) along with a Web Service API. Developers will be able to choose their “favorite PaaS” out of several on their chosen IaaS, and get a well defined programming model and a well defined set of APIs for that specific PaaS.
So IaaS “wins” in the sense that it is a required offering for all major vendors; while PaaS “wins” in the sense that it makes life easier for the developer. The developer will go to PaaS for speed of getting results, and to IaaS when she needs the nuts-and-bolts of the cloud.
IaaS will “go into the background” about as much as the Linux or Windows OS-s have “gone into the background” in the past 10 years… In fact they have done just that, but it hasn’t hurt them one bit.