In the last four years, application platform technologies offered on the cloud—also known as Platform-as-a-Service—have gone through a great deal of churn and turmoil. Companies like Coghead and Dabble DB folded, technologies like CloudFoundry have gone through a phase of reinvention, and players like Rollbase and LongJump have been acquired by major software vendors Progress Software and Software AG, respectively.

Additionally, after pushing its abstracted platform in its first iteration of the Azure cloud, Microsoft shifted strategy to emphasize its IaaS (Infrastructure-as-a-Service) offering as it continues to invest in data centers to challenge Amazon Web Services in offering virtual machine instances on a granular pay structure.

Finally, we are seeing a proliferation of mobile-specific offerings to handle back-end development for mobile application builders, and many of these are adding abstracted computation services. These offerings, known as Mobile-Backend-as-a-Service (MBaaS), and exemplified by players like StackMob, FatFractal and Parse (which was recently acquired by Facebook), are encroaching on the PaaS market and its value proposition. In this column, we will review the state of PaaS today and touch on its potential future.

What is PaaS?
Cloud architectures are Internet-based and have characteristics such as self-service provisioning and management; dense resource pooling; automated elastic scaling and workload balancing; failure resilience and self-recovery; and fine-grained resource-consumption metering. PaaS is a set of abstracted application-platform services offered with features that support cloud architectures. PaaS offerings range from isolated application-platform services such as databases, compute and testing, to more cohesive cloud application-platform offerings that enable application development and deployment. IDC has surveyed the PaaS landscape and found more than 40 such PaaS offerings in production today.

(More on PaaSes: Public or private: Which PaaS is right for you?)

Stepping back and looking at the various PaaS offerings available, it is easy to be bewildered by the range of capabilities and diversity of styles. In addition to the varying feature sets and types of underlying infrastructure supported (virtualization, private clouds or public IaaS), these offerings differ in the abstraction levels presented to the developer.

This is not surprising because traditional application platforms that have emerged over the last half-century of computing have also presented varying abstraction levels, targeting different developers. The traditional trade-offs between developer productivity enabled by abstraction and its limitations in handling complex requirements are present in PaaS as well.

IDC sees two kinds of PaaS offerings on the market today: offerings focused on application construction (often utilizing model-driven techniques with high-level scripting languages), and offerings focused on deploying applications built with standard programming languages. The two types cater to different needs in the industry, the first primarily toward highly efficient development, the latter toward efficient deployment and management.
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Model-driven PaaS
The most mature PaaS offerings on the market are of the model-driven variety. These solutions, derived from or built in the mold of traditional database-oriented application platforms and 4GL offerings, specialize in a class of applications often used in small organizations and departmental settings. Most are designed for the knowledge-worker-turned-developer, but some are aimed at citizen developers, requiring even less development skills.

While most of these offerings are proprietary in nature where applications cannot be ported, users tend to stick with them because of the their productivity. In the last 12 months, we have seen players like LongJump and Rollbase be acquired by Software AG and Progress Software respectively, highlighting the value of such platforms to certain integration and extensibility requirements to existing platform players. Other players in this space, such as MioSoft and TrackVia, have remained independent. Some of the more mature players, like Magic Software and Servoy, have successfully targeted application vendors. Still others, like Intuit’s QuickBase, Zoho Creator and Salesforce.com’s Force.com (the market leader in the space), initially offered their platforms primarily as tools to extend their application offerings.

Deployment PaaS
A newer category of PaaS offerings focuses on developer needs for hosting applications developed with general-purpose programming languages such as Java, PHP and Ruby. These offerings do not usually provide authoring tools—relying instead on standard IDEs such as Eclipse or NetBeans—and they support a curated approach to application deployment and operation.

Instead of providing VMs such as those with Amazon Web Services or Microsoft Azure, they allow developers to run their code in abstracted containers that are efficiently provisioned by the infrastructure. The key value is that developers do not have to manage OS images, and are able to take advantage of policy-based scaling and availability services built into the offering.

The future of PaaS
PaaS offerings are going through extremely rapid evolution, and players are churning their software rapidly, adding features and refining their positions. The reality that most PaaS vendors face is that developers do not like to spend a great deal of money, and once applications mature, many developers take them to IaaS players where compute costs often are lower.

Another major barrier is that PaaS offerings are not compatible with each other, and developers have to adapt their applications to specific offerings. In particular, many legacy applications running inside enterprises today are not easily adapted to these offerings, even if PaaS is able to support the programming language because the solutions often provide constraints on local storage and application states that require modifying application code.

Cloud platform offerings are evolving and honing their focus on specific market workloads and market opportunities, such as mobile developers giving rise to the MBaaS category. The opportunity in PaaS remains exciting and fast-moving, so developers need to keep their eyes open.

Al Hilwa is program director of application development software at IDC.