Docker is a hot property. Thousands of people on GitHub are either involved with or following the project, but the lion's share of the contributions can be traced back to a few key entities -- and one of them may have more people working on Docker than Docker itself.
Arun Gupta, director of technical marketing and developer advocacy at Red Hat, recently posted a set of numbers crunched from Docker's GitHub data, apparently generated by the gitdm utility, revealing the corporate affiliations of the major contributors to Docker. Not surprisingly, the single biggest named contributor is Docker, which has the most lines changed and the most number of change sets.
In second place is Red Hat (7.3 percent of change sets, 7.8 percent of lines changed). It's a reflection of the company's reorientation of its Linux platform away from generic enterprise infrastructure and toward containers, with at least 42 developers at Red Hat working on container-related projects. A similar search on the Docker-related Kubernetes project revealed statistics that showed Red Had devoting about as many developers to that project as well.
Red Hat's 42 listed contributors to Docker outpaces Docker itself, which has 30. Some of that may be due to people at Red Hat who worked on the project for a short time and haven't contributed as recently, but Docker's newness (the project is a little more than two years old) might offset that effect.
In third place is IBM. Its total complement of changes and active hackers is around a quarter of Red Hat's own, 12 people to Red Hat's 42. Like Red Hat, it's involved with the Docker project as part of its general retooling effort around containers (and other technologies). Unlike Red Hat, the number of people devoted to this work within IBM is minuscule compared to the company's total size.
The rest of the companies listed are familiar names: Google, Cisco, VMware, and CoreOS. One other name in the running stands apart from that crew: Amadeus, an IT solutions provider for travel and tourism. Its appearance hints at how companies not broadly associated with a given technology can still participate in its development. (The company has a session listed at the forthcoming Red Hat Summit in June 2015, where it will discuss its use of Docker and Kubernetes in conjunction with OpenShift.)
One detail that makes the results more difficult to parse is the number of contributions listing no employer at all. Almost half of all the change set contributions -- 47.9 percent -- were not attributed to a particular employer. The easiest reading of that number: It represents many individual hackers contributing spot changes, perhaps flagging bugs, adding minor features, or providing examples for the documentation. In fact, Docker has been seeking to bolster that last item at least as much as the Docker code itself.
[Edited to update link to Kubernetes statistics to a more accurate list.]