Docker
Docker uses LXC to create and manage native, sandboxed virtual containers. LXC containers acts like a separate OSes, can install their own packages without affecting anything else, and overall have almost the same flexibility of VMs but without any of the virtualization overhead! Docker adds a ton of features, like an elegant configuration file that automates many things (like port forwarding, disk/directory mounting, networking, etc), a way to create and share readymade images that can be distributed as appliances, etc.
linux open-source virt cloud-paas provisioning go
LXD
LXD is a next generation system container manager. It offers a user experience similar to virtual machines but using Linux containers instead. It's image based with pre-made images available for a wide number of Linux distributions and is built around a very powerful, yet pretty simple, REST API.
linux open-source virt cloud-paas provisioning go
Monit
An open source utility for managing and monitoring processes, programs, files, directories and filesystems
linux osx open-source monitoring process-mgmt c
PowerShell Desired State Configuration
DSC is a new management platform in Windows PowerShell that enables deploying and managing configuration data for software services and managing the environment in which these services run.
linux windows powershell open-source commercial config-mgmt