What is Docker?

Docker is a software platform for building applications based on containers—small and lightweight execution environments that make shared use of the operating system kernel but otherwise run in isolation from one another. While containers have been used in Linux and Unix systems for some time, Docker, an open source project launched in 2013, helped popularize the technology by making it easier than ever for developers to package their software to build once and run anywhere.

What are Containers? Understanding Docker Fundamentals
Docker started out in 2012 as an open source project, originally named dotcloud, to build single-application Linux containers. Since then, Docker has become an immensely popular development tool, increasingly used as a runtime environment. Few -- if any -- technologies have caught on with developers…

A brief history of Docker

Founded as DotCloud in 2008 by Solomon Hykes in Paris, what we now know as Docker started out as a platform as a service (PaaS) before pivoting in 2013 to focus on democratizing the underlying software containers its platform was running on.

Hykes first demoed Docker at PyCon in March 2013, where he explained that Docker was created because developers kept asking for the underlying technology powering the DotCloud platform.

We did always think it would be cool to be able to say, Yes, here is our low-level piece. Now you can do Linux containers with us and go do whatever you want, go build your platform.’ So that’s what we are doing.

And so Docker was born, with the open source project quickly picking up traction with developers and attracting the attention of high-profile technology providers like Microsoft, IBM, and Red Hat, as well as venture capitalists willing to pump millions of dollars into the innovative startup. The container revolution had begun.