More than 1,500 developers, operators and managers are gathering in Santa Clara, CA this morning for the two-day Cloud Foundry Summit, highlighting the popularity of the new breed of development platforms that are specific to the cloud. Pivotal Software, Inc.’s Cloud Foundry is just one of a diverse and growing lineup of so-called platform-as-a-service (PaaS) suites that have sprung forth from nearly every major software and infrastructure player in the cloud, and they present some clear-cut choices for customers.

But they also present some confusion about just what PaaS is and how it relates to the the other as-a-service options that are proliferating in the market, particularly since some PaaS suites come integrated with infrastructure-as-a-service (Iaas). We asked Wikibon analysts to provide clarity.

What the heck is PaaS?

PaaS is essentially a development platform in the cloud. According to WhatIs.com, “In a PaaS model, a cloud provider delivers hardware and software tools — usually those needed for application development — to its users as a service. A PaaS provider hosts the hardware and software on its own infrastructure. As a result, PaaS frees users from having to install in-house hardware and software to develop or run a new application.”

But PaaS is of value to more than just developers. The platform can also be used to integrate or add new functionality to existing applications. And you don’t need to be a programmer to get value. One of the appeals of ServiceNow, Inc.’s Service Automation Platform, in fact, is that it can be used by so-called “low-code and no-code developers” to automate tasks without a lot of programming.

“The core reason you’d need PaaS is to rapidly deploy your own apps, other apps, changes to apps and reduce the time to value,” said Wikibon co-founder David Floyer.

PaaS platforms have been an important driving force in the evolution of DevOps, a development technique in which code and revisions are quickly made live. Cloud service providers promise that applications developed with their tools will run in production just like they do in test, thereby avoiding the nasty surprises that often occur when code is moved from a development to a production environment.

Three types of PaaS

One of the things that confuses people about PaaS is that it sounds a little like public cloud, or infrastructure as a service (IaaS). In fact, the two are often intertwined and in some cases combined, as is the case with Pivotal Software, Inc.’s CloudFoundry. All of the major public cloud providers also have their own PaaS platforms. You can also get PaaS services from some of the big software as a service (SaaS) companies, like Salesforce.com, Inc. and ServiceNow. Or you can opt for integrated PaaS/IaaS bundles. Wikibon defines three different types of PaaS cloud services. Let’s look at the trade-offs of each.

PaaS integrated with IaaS

Examples: Pivotal Software, Inc.’s Cloud Foundry, IBM Bluemix, Hewlett-Packard Co.’s Helion Development Platform, Red Hat, Inc.’s OpenShift.

Pros: Low cost; flexibility to deploy easily on any supported infrastructure platform; supports a wide range of languages and tools; low risk of platform lock-in; good skills portability; good for hybrid clouds.

Cons: Lacks IaaS platform-specific functionality; applications may run more slowly on unsupported platforms.

Wikibon Analyst quote: “This is the next generation of Java, with all the good and bad that comes with it.” – Stu Miniman

PaaS on top of IaaS

Examples: Amazon Elastic Beanstalk, Microsoft .Net,, Google App Engine

Pros: Excellent integration with underlying IaaS platform; rapid migration from test to production; good vendor support.

Cons: Platform lock-in; limited extensibility; may not support hybrid clouds; skills may not be portable

Wikibon Analyst quote: “This is the mother of all lock-ins. The idea is to free you from your infrastructure but lock you into a framework.” – David Vellante

PaaS on top of SaaS

Examples: Salesforce.com Salesforce1, ServiceNow Service Automation Platform, SAP HANA Cloud Platform.

Pros: Excellent integration with SaaS application; rich set of platform-specific tools; accessible to non-programmers; rapid deployment; good vendor support.

Cons: Tools may not be appropriate for general purpose use; proprietary tools create platform lock-in; skills may not be portable.

Wikibon Analyst quote: “The benefit is time-to-value and efficiency. Consider the overhead of running applications as a service as opposed to on bare metal.” – David Floyer

The road ahead

PaaS is a vibrant and healthy market with a bright future. “There will always be a lot of choices out there because every company wants to play in this space, and the technology moves so fast that innovation will continuously shake up the mix,” says Wikibon’s Vellante.

In an IaaS market that constantly flirts with becoming a commodity, PaaS provides a differentiation point that has real customer value. It also has the potential for lock-in, so IT organizations need to consider how important portability and openness are to them. No one size will fit all.

New choices will become available. When entrants to the applications or platforms markets achieve critical mass, they invariably introduce toolsets to help build an ecosystem. That has implications for skills and resource allocation among their customers.

“What matters most is the strategic fit for your organization,” Vellante advises. “The factors that determine which platforms you should use are the productivity of your developers, the ecosystem you’re targeting and its affinity to your business. Lock-in is a concern, but at the same time you may have access to a rich set of tools that counterbalance the risks.”