Paas plus pointsPlatform as a Service (PaaS) is one of the many important forms of the cloud these days, and perhaps it’s also the least understood.

If we think of the cloud as a stack, one can see three layers starting from the bottom:

IaaS – Infrastructure as a service is just as it sounds. Instead of having server, storage and network infrastructure in-house, you rent these from a cloud provider. These start out as relatively raw services, largely mimicking the hardware they replace. Best example – Amazon Web Services (AWS).

PaaS – PaaS is, as the term is strictly known, like taking IaaS and adding additional layers to run and develop applications. Best example of this is the early versions of Microsoft Azure.

SaaS – Software as a Service is the highest level of this stack where applications normally running in-house are in the cloud. The best example is Salesforce.com.

PaaS is akin to having a software development workstation in the cloud. This narrow use of the term is now just one aspect of PaaS. In fact, Gartner has confused matters greatly, at least in my mind, with the term Enterprise Application Platform as a Service (aPaaS) which includes both what I consider pure PaaS such as Microsoft Azure with some more SaaS-style players.

Here’s how Gartner uses the term. “A PaaS that is designed to enable runtime deployment, management and maintenance of cloud business application services is an application PaaS (aPaaS).

An aPaaS that is designed to support the enterprise requirements for business applications and application projects is an enterprise aPaaS,” the company wrote in last year’s Magic Quadrant for Enterprise Application Platform as a Service.

Saleforce.com is the highest ranking vendor in Gartner’s aPaaS magic quadrant. Interestingly, Salesforce.com is technically more akin to the basic notion of PaaS. “Salesforce.com’s Salesforce1 Platform is an enterprise cloud platform that lets companies build and deliver custom apps faster to connect employees, customers, and products. The Salesforce1 Mobile App, also launched last fall, can quickly make many of these apps mobile with a few admin setting clicks,” Salesforce.com explains on its web site. So who is right?

PaaS confusion

In this part of the analysis, we’ll use the conventional development focused aspect of PaaS, even though one of the benefits of PaaS for developers is to be able to then run and update that application in the same PaaS cloud in which it was written.

It was also so simple when that was the very definition of PaaS. But things are a’ changing and part of the new confusion is that IaaS makers have been adding PaaS features, and PaaS players have been adding IaaS items. Even SaaS players are getting into the game. Saleforce.com, for instance, is making its platform more developer-friendly with PaaS features. This way you can modify your Salesforce.com application using the company’s own services. That is aside from its more pure-play Salesforce1 Platform PaaS offering.

Gartner sees all this flux as greatly impacting PaaS.

“Of all the cloud technological aspects, infrastructure as a service (IaaS) and software as a service (SaaS) are the most mature and established from a competitive landscape perspective, while PaaS is the least evolved,” said Fabrizio Biscotti, research director at Gartner in analyzing the market. “For this reason, PaaS is where the battle between suppliers and products is set to intensify the most.”

While PaaS is moving in many different directions, its core original value of giving developers a new way to write, deploy and iterate applications remains steadfast.

Why PaaS is hot

As if software development isn’t hard enough, coders often have to deal with the underlying hardware, all those servers, disk arrays and network adapters. Not just that, operating systems have to be maintained, along with the development environments, usually through an integrated development environment (IDE) such as Microsoft Visual Studio. And you need to multiply the client part by the number of programmers on the job.

Putting that in the cloud (or a private cloud for that matter) relieves this IT burden, and it makes it a lot easier for developers to collaborate, deploy software and iterate.

David S. Linthicum, writing for GigaOM in October last year, is bullish on PaaS growth. “The numbers are all over the place. However, based upon our estimations, the PaaS market is expected to reach @ $7.5bn by 2016 and grow at a compound annual growth rate (CAGR) of about 50%,” he wrote.

Like me, Linthicum sees lots of overlap and blurriness between all the cloud stack categories.

“One of the larger issues is that PaaS and IaaS have really crossed features. There are pure PaaS providers, such as EngineYard. However, the largest PaaS players, including Microsoft and Google, now offer deep IaaS services as well. The 800-pound IaaS public cloud provider, AWS, now offers PaaS capabilities. Thus, it’s hard to determine where the IaaS stops, and the PaaS begins. Or, the other way around,” he wrote.

While 50% CAGR sounds great, it could be better Linthicum argued. Here are two reasons Linthicum said PaaS isn’t growing faster:

Enterprises aren’t fast enough in adopting PaaS, which is mainly due toa lack of understanding of what PaaS is and what limitations are there with public and private PaaS. Linthicum continues by saying that PaaS is still a tough sale, as enterprises seem to be more comfortable with traditional development tools.

Lock-in is a worrying factor when choosing PaaS. Even though options such as Docker are now available, many in enterprise development worry that applications built on PaaS clouds won’t be easy to move from cloud-to-cloud. Unfortunately, that fear doesn’t come out of nowhere. Extra work is needed to move apps built so lock-in is an issue to take into consideration.

One answer to a better PaaS may be to stop making the distinction. IaaS and PaaS are blending for a reason – large customers seem to want it that way. “For the larger players, including AWS, Google, and Microsoft, the path might just be to remain on course. Enterprises seem to want to adopt PaaS providers that also provide IaaS, and the other way around,” Linthicum wrote.

Pure PaaS players have a bigger challenge in defining and proving value, despite the seeming logic of their approach. There are several paths to development as Linthicum explains and it is important that a proof of concept is created to make sure PaaS in the right way to go and what kind of PaaS technology is to be used.

What are your thoughts? Have you ever considered or are you considering using PaaS in a future project? Let us know in the comments section below.