Podman, Buildah, and CRI-O are new open source projects that address early concerns with Docker like requiring a daemon, secret handling issues, and root/privileged concerns. Podman is a daemonless container engine that provides a Docker-compatible command line. Buildah is a tool for building OCI container images without needing a daemon. CRI-O implements the Kubernetes Container Runtime Interface for running containers securely in production clusters without daemons.