Docker has generated the kind of excitement rare for a rookie open source project. Its purpose is to enable the easy creation of lightweight, portable, self-sufficient containers from any application. The same container that a developer builds and tests on a laptop can run at scale, in production, on VMs, bare metal, OpenStack clusters, public clouds, and more.
Docker was started by a small, commercial firm known as dotCloud, but the project has grown roots and turned the heads of the big names, including Red Hat and Google. The level of portability delivered by Docker offers companies plenty of options for where their apps will run, while giving developers freedom of choice in the languages and tools used to build them.