> but it would be worth a lot if I could run any image on any platform.
That technology exists, it is called a VM. Any platfrom that supports x86 for example will run any x86 compatible image. You can use wrappers and scripts like Vagrant on top of it.
Or if you want all hosting managed as a pool of resources (storage, CPU) try something like oVirt.
> and doesn't address any of the reasons why people prefer containers to VMs for some types of workloads
I was responding to one reason -- which is "running any image on any platform".
> why people prefer containers to VMs for some types of workloads
Sure but there are no magic unicorns underneath, knowing what you get from a technology requires some understanding on how it works. Saying things like "I want very lightweight but also want it to run any image on it" is asking for a trade-off. Or a complicated multi-host cabaility based platform.
That technology exists, it is called a VM. Any platfrom that supports x86 for example will run any x86 compatible image. You can use wrappers and scripts like Vagrant on top of it.
Or if you want all hosting managed as a pool of resources (storage, CPU) try something like oVirt.
http://www.ovirt.org/About_oVirt