crun vs Kata Containers

crun is a free, self-hosted OCI container runtime for Linux, written in C. It conforms to the OCI Container Runtime specifications and provides CLI operations for creating, running, executing commands in, listing, pausing, resuming, updating, checkpointing and restoring containers. It can generate a configuration for unprivileged use and creates a user namespace when run by a non-root user. The project documents integration with Podman, an Ansible role for installing a statically linked binary and a Lua binding. Build instructions cover Fedora, RHEL/CentOS Stream 9 and 10, Ubuntu, Alpine and openSUSE Tumbleweed; release binaries are listed for Linux amd64 and arm64, including variants without systemd. Official release artifacts are signed, with GPG verification commands provided. The project reports a benchmark of 100 sequential `/bin/true` containers completing in 1.69 seconds with crun versus 3.34 seconds with runc on the author's machine. The manual marks cgroup v1 support as deprecated. Regular patch releases target the latest version; fixes for earlier versions are best effort and not guaranteed.

Kata Containers is a free, open-source Linux container runtime that uses lightweight virtual machines for workload isolation while remaining compatible with the container ecosystem. Each workload runs in a dedicated kernel, separating network, I/O, and memory; hardware virtualization can provide an additional defense layer. The runtime supports OCI container images, the Kubernetes CRI interface, and integrations with Docker and Kubernetes. Supported hypervisors include QEMU, Cloud Hypervisor, and Firecracker. Listed hardware includes Nvidia GPU, FPGA, QAT, RDMA, and SR-IOV, with x86_64, aarch64, ppc64le, and s390x architectures. Kata requires nested virtualization or bare metal, and kata-check can check host capability. Installation guides cover CentOS, Debian, Fedora, OpenSUSE, RHEL, SLES, and Ubuntu. Listed cloud platforms include Amazon Web Services, Microsoft Azure, Google Compute Engine, and Vexxhost OpenStack Cloud. The Apache 2.0 license permits use and distribution. Only the current monthly release series receives security fixes; older releases are unsupported and there are no long-term-support branches.