Also LXC has been in the kernel longer and seems more mature (since 2.6.20-something).
LXC in the kernel? It's a userspace toolkit that makes use of kernel technologies (namespaces, pivot_root, cgroups...), but I don't recall it being bundled as a part of it.
Sorry, I meant LXC support. Yeah it is comprised of a set of a features supported by regular Linux kernels + userspace tools. The feature set has been there for a quite a while.
> but I don't recall it being bundled as a part of it.
But it is in contrast to say OpenVZ which required patching the kernel to work.
I like LXD a lot, but it's simply too new to rally behind it fully. You have to backport it to Ubuntu 14.04 if you even want to run it on an LTS operating system.
That being said, I think Canonical has good vision and will execute. LXD combines the best from old and new school.
Can have application structured as multiple processes so can map VM patterns to it easier, without creating unnecessary containers.
Believe you also get better security between containers
Also LXC has been in the kernel longer and seems more mature (since 2.6.20-something).