The main three concepts behind Popper are Linux containers, the container-native paradigm, and workflows. This page is under construction, we plan on expanding it with our own content (contributions are more than welcome)! For now, we provide with a list of external resources and a Glossary.


  • Linux containers. An OS-level virtualization technology for isolating applications in a Linux host machine.
  • Container runtime. The software that interacts with the Linux kernel in order to provide with container primitives to upper-level components such as a container engine (see “Container Engine”). Examples of runtimes are runc, Kata and crun.
  • Container engine. Container management software that provides users with an interface to. Examples of engines are Docker, Podman and Singularity.
  • Container-native development. An approach to writing software that makes use of containers at every stage of the software delivery cycle (building, testing, deploying, etc.). In practical terms, when following a container-native paradigm, other than a text editor or ID, dependencies required to develop, test or deploy software are NEVER installed directly on your host computer. Instead, they are packaged in container images and you make use of them through a container engine.
  • Workflow. A series of steps, where each step specifies what it does, as well as which other steps need to be executed prior to its execution. It is commonly represented as a directed acyclic graph (DAG), where each node represents a step. The word “pipeline” is usually used interchangeably to refer to a workflow.
  • Task or Step. A node in a workflow DAG.
  • Container-native workflow. A workflow where each step runs in a container.
  • Container-native task or step. A step in a container-native workflow that specifies the image it runs, the arguments that are executed, the environment available inside the container, among other attributes available for containers (network configuration, resource limits, capabilities, volumes, etc.).