VMware announced two container platforms today, including one aimed at all-container deployments that potentially wouldn't use virtual machines.

The announcements continue VMware's cautious dance with containers. There's a suspicion that containers could someday supplant virtual machines in the data center. But VMware — and many others, to be honest — think the two structures make a pragmatic combination.

It all fits VMware's pledge last year to work on "delivering industrial strength infrastructure underneath containers," said Raghu Raghuram, executive vice president for the software-defined data center (SDDC), during a Monday morning press conference at VMworld. (The photo above is Raghuram at the keynote a couple of hours later.)

The problem with the VMs-plus-containers plan is that the resource efficiency of containers — the ability for many of them to share CPU and memory — can be hobbled by the size of VMs.

More properly, the burden is the size of the operating system that comes with VMs, said Kit Colbert, vice president and CTO of cloud-native applications, during a press conference Monday.

That's led to a charge to slim down virtualization to better fit the container world. Efforts along those lines include Canonical's LXD hypervisor, Citrix's App Adapter, Intel's Clear Containers, and the Hyper_ project.

Now, VMware is doing the same with today's announcement of the Photon Platform.

It includes two components. The first is the Photon Machine, which combines the core engine of ESX ("we call it a microvisor" sometimes, Colbert said) and the Photon OS, which is VMware's container-friendly Linux distribution. The Photon Machine gets installed on data center servers; it's an OS-plus-hypervisor combination, but "just the core set that you need to run this lightweight virtualization," Colbert said.

This development came from a customer's request, Raghuram said. "What they want is the robustness of ESX and its ability to connect to a wide range of devices ... combined with the Photon OS," Raghuram said. "What they did not have a need for was some of the other things that ESX did."

The other component is the Photon Controller, which manages clusters of virtual machines. That's the direction containers are pushing virtualization in: managing VMs in large groups rather than individually, Colbert said.

To that end, Photon will use APIs and will support platforms such as Kubernetes, Mesos, and Pivotal Cloud Foundry (Pivotal being a sibling of VMware's in the EMC Federation of companies.)

Photon OS is a Linux distribution tailored for container support; VMware open-sourced it in April. It supports multiple container formats including CoreOS' rkt and, of course, Docker.

The Photon Controller is due for private beta availability in the fourth quarter.

For the installed base that wants to combine containers with a vSphere framework, VMware is doing the obvious thing: offering what it's calling vSphere Integrated Containers. They're being shown as a technology preview at VMworld, with beta availability slated for 2016.

The concept is being pitched as a way to let IT support any application, containerized or not, through vSphere. "It essentially makes containers a first-class citizen within vSphere," said VMware CTO Ray O'Farrell during Monday's press conference.