There has never been a new technology introduced in IT that penetrated the landscape so quickly and so thoroughly than containers. Any company that doesn't want to be left behind cannot ignore containers. This huge interest in containers from all sectors of the industry has triggered a lot of innovation in this sector. Numerous companies have specialized in containers and either provide products that build on top of this technology or build tools that support it.
Initially, Docker didn't have a solution for container orchestration thus other companies or projects, open source or not, tried to close this gap. The most prominent one is Kubernetes which was initiated by Google and then later donated to the CNCF. Other container orchestration products are Apache Mesos, Rancher, Red Hat's Open Shift, Docker's own Swarm, and more.
More recently, the trend goes towards a service mesh. This is the new buzz word. As we containerize more and more applications, and as we refactor those applications into more microservice-oriented applications, we run into problems that simple orchestration software cannot solve anymore in a reliable and scalable way. Topics in this area are service discovery, monitoring, tracing, and log aggregation. Many new projects have emerged in this area, the most popular one at this time being Istio, which is also part of the CNCF.
Many say that the next step in the evolution of software are functions, or more precisely, Functions as a Service (FaaS). Some projects exist that provide exactly this kind of service and are built on top of containers. One prominent example is OpenFaaS.
We have only scratched the surface of the container ecosystem. All big IT companies such as Google, Microsoft, Intel, Red Hat, IBM, and more are working feverishly on containers and related technologies. The CNCF that is mainly about containers and related technologies, has so many registered projects, that they do not all fit on a poster anymore. It's an exciting time to work in this area. And in my humble opinion, this is only the beginning.