DriftVM is a lightweight manager for LXC containers and KVM machine. I made this versus using Proxmox because I like to run my LXC containers in one big shared FS instead in LVM/disk images/etc. so I don't have to worry about growing/shrinking them. Proxmox has no way to do this (as far as I could tell) so I put this together for my own use but figured I would share. Although it does support using disk images for LXC if you like and of course for KVM. It is intended more for a home server than commercial use.
Check it out at GitHub. PRs are welcome of course.