Early Docker supporter CoreOS is working on its own container management system that will compete with Docker, which CoreOS leadership believes has lost its way.

CoreOS CEO Alex Polvi unveiled Rocket in a company blog. A new container runtime designed for composability, security and speed, Rocket is only currently available as a prototype through Github, but the company is looking to gather feedback from the community and work towards getting the container system to market.

In his blog, Polvi commended Docker and the ideas floating around it when it launched in 2013. He noted the idea of a "standard container" as being "striking and immediately attractive," but according to the CoreOS CEO, the Docker focus has changed since it originally launched.

Click here for Talkin' Cloud's Top 100 CSP list

"Unfortunately, a simple re-usable component is not how things are playing out. Docker now is building tools for launching cloud servers, systems for clustering, and a wide range of functions: building images, running images, uploading, downloading, and eventually even overlay networking, all compiled into one monolithic binary running primarily as root on your server," he wrote. "The standard container manifesto was removed. We should stop talking about Docker containers, and start talking about the Docker Platform. It is not becoming the simple composable building block we had envisioned."

CoreOS appears to be taking the original Docker vision and reimagining the technology itself. Polvi noted that CoreOS is sticking close to the original Docker ideals, but it's also "cleaning up and fixing a few things" he would like to see in a production-ready container.

Docker is still catching on, but it has generated a lot of interest within the cloud community. A rival could potentially make things even more interesting. CoreOS seems intent on keeping Rocket separated from its own products.

The company isn't abandoning Docker, either. Polvi hinted at some upcoming announcements, but he also wrote that CoreOS will continue to support Docker.