darthcamaro writes: Docker is about to get some real competition in the container runtime space, thanks to the lofficial aunch of rkt 1.0. CoreOS started building rkt in 2014 and after more than a year of security, performance and feature improvement are now ready to declare it 'production-ready.' While rkt is a docker runtime rival, docker apps will run in rkt, giving using a new runtime choice: "rkt will remain compatible with the Docker-specific image format, as well as its own native App Container Image (ACI). That means developers can build containers with Docker and run those containers with rkt. In addition, CoreOS will support the growing ecosystem of tools based around the ACI format."