Count Apprenda in those ranks as well. The Troy, N.Y. company offers technology — dubbed Platform as a Service — that business customers can use to create and maintain specialized software. Apprenda’s PaaS can run in a company’s internal data center for IT folks still not comfortable with public cloud infrastructure. And, it can run on public clouds such as Amazon Web Services or Microsoft Azure. Or both.

Now, to help large corporate customers still leery of giving up control of their IT departments to the public clouds, Apprenda is supporting Docker containers. Docker is the latest software darling coming out of Silicon Valley because it lets developers write applications and assign them just the computing resources they need, all in one efficient package. This is seen as more efficient than running multiple applications in a virtualized manner because the virtualization layer soaks up system resources, making your software run more slowly.

Docker makes it easy for software developers to write applications that run in both in the cloud and on-premises, said Apprenda CEO Sinclair Schuller via email. “The problem is that Docker alone is a bit like the wild-west: you can do whatever you want. Unfortunately, most large corporations can’t allow that sort of flexibility because of the inherent risk it comes with.”

To be sure, pretty much the entire software universe has blessed Docker already, but Apprenda’s pitch is that it supports a wide range of underlying technologies running in customer sites.

PivotalCF, which plans to add Docker support via a new Lattice framework, appears aligned with VMware’s technology; Red Hat’s OpenShift is pretty much tied to Red Hat Enterprise Linux operating system. Apprenda, supports Java, Microsoft .Net, OpenStack and a raft of foundational technologies from different vendors, and just added IBM to the mix with support for IBM WebSphere application servers.

The fact that Microsoft and IBM offer their own PaaSes shows just how intertwined, not to mention confusing, the software universe is when it comes to these platforms.

Since very few companies are 100 percent Microsoft or IBM or Red Hat shops, Schuller sees an opportunity. He said Apprenda’s goal is to work with the applications companies already run to bridge the gaps between those technologies. Toward that end, the company, which started out focusing on Microsoft .NET applications, has long since added support for Java, OpenStack and other key technologies. That means in-house developers can keep running and tweaking those older applications. But, Apprenda also gives them a runway to create new, born-to-the-cloud applications that run on OpenStack, Azure, AWS or what-have-you.

Said Schuller: “All large corporations are writing more software to be competitive. Nobody wants to be the next Blockbuster or Barnes & Noble. PaaS is the engine that equips the world’s biggest companies to quickly and efficiently write new applications so they can compete in a software-driven world.”