Container runtime specifications

Pouch is a Linux container runtime and OCI container engine designed to execute containerized applications. It functions as a Kubernetes container runtime, integrating with orchestrators to manage the lifecycle of pods and isolated application environments. The project features a peer-to-peer image distribution system to deliver large container images across large-scale clusters while reducing bandwidth load. It also provides support for legacy Linux kernel versions, allowing modern container runtimes to maintain compatibility with older hardware. The runtime implements application isolation

crun is a low-level container runtime that implements the Open Container Initiative specification for managing the lifecycle of isolated processes. It provides the core mechanisms for container creation, execution, and deletion, ensuring compatibility across platforms through standardized lifecycle management. The project distinguishes itself by offering a shared C library that allows container runtime operations to be embedded directly into other compiled applications. It further extends execution capabilities through specialized handlers that enable the deployment of containers within isola

Youki is a low-level container runtime written in Rust that creates and manages isolated containers according to Open Container Initiative specifications. It serves as an execution engine that can function as a rootless container manager or a pluggable Kubernetes CRI runtime to manage pods and containers within a cluster. The project distinguishes itself by providing a Wasm container runtime capable of executing WebAssembly modules as isolated workloads compatible with standard orchestration tools. It further supports a rootless execution model, allowing isolated environments to start as non-

Containerd is a daemon-based container runtime that manages the complete lifecycle of containers on a host system. It functions as a core orchestration backend, handling image distribution, storage, and process execution while adhering to industry-standard specifications for container execution and configuration. The project is distinguished by its modular, plugin-based architecture, which allows for the extension of storage, runtime, and networking capabilities without requiring a full daemon recompile. It utilizes a shim-based execution model to delegate low-level operations, ensuring isola

The project provides an open container runtime specification and standardized schema for defining container configurations, namespaces, resource limits, security policies, and filesystem mounts across platforms. It outlines the formal configuration formats, lifecycle operations, and execution environments necessary for portable, isolated container workloads. The specification covers container lifecycle management protocols and structured rules governing container creation, execution startup, process signaling, state tracking, and resource teardown. It standardizes local bundle packaging and

This project is an OCI-compatible container runtime that executes workloads within lightweight virtual machines. By leveraging hardware-based virtualization, it provides strong security isolation between containerized processes and the host operating system, serving as a drop-in replacement for traditional container execution environments. The runtime distinguishes itself through a hypervisor-agnostic architecture that abstracts underlying virtualization operations, allowing for consistent container lifecycle management across different backends. It integrates directly with standard container

Youki is an OCI container runtime written in Rust. It implements the Open Container Initiative runtime specification to manage the lifecycle of containerized processes and ensure compatibility with standard container images and engines. The runtime is designed for memory safety and supports rootless container execution, allowing containers to run as non-root users to reduce security risks and limit privilege escalation. It provides core container management capabilities, including spawning and managing OCI containers. This is achieved through Linux namespace isolation, cgroup-based resource

Docker CE is an OCI compliant container platform and runtime engine used for building and running applications within isolated environments. It functions as a Linux container orchestrator and provides a command-line interface to manage the entire lifecycle of running application instances. The platform enables containerized application deployment and cross-platform software distribution by packaging software with its dependencies. It supports microservices architecture management and the creation of reproducible local development environments. The system includes capabilities for application

This project is a secure container runtime that provides strong isolation for application workloads by implementing a userspace kernel. By intercepting system calls and executing them within a memory-safe, restricted environment, it minimizes the attack surface exposed to the host kernel. It functions as a drop-in engine for standard container orchestration platforms, ensuring compatibility with industry-standard runtime specifications while maintaining a hardened execution boundary. The runtime distinguishes itself through its ability to virtualize core system resources, including an indepen

CRI-O is an open-source container runtime that implements the Kubernetes Container Runtime Interface (CRI) to manage container images, pods, and containers on cluster nodes using OCI-compatible runtimes. It serves as a node-level container manager that handles image pulling, container lifecycle, and resource monitoring for Kubernetes clusters, running containers according to the Open Container Initiative specifications. The runtime distinguishes itself through live configuration reloading that applies changes to runtime definitions, registry mirrors, and TLS certificates without restarting th

Moby is an OCI container engine and runtime manager designed for building, running, and managing isolated containers based on Open Container Initiative standards. It functions as a container daemon and image builder, providing a core engine to orchestrate the full lifecycle of containers and the packaging of source code into portable images. The project provides a standardized HTTP interface that allows for programmatic container management, enabling external clients to control daemon settings and container operations. It supports a rootless security model, allowing the engine daemon to execu

rkt is a pod-native container engine and runtime for Linux that executes containerized applications as isolated pods. It serves as an OCI container runtime and a Linux container manager, supporting the execution of images based on Open Container Initiative, appc, and Docker specifications. The project distinguishes itself by offering hardware-level container isolation, allowing pods to run within virtual machines using KVM or QEMU for a dedicated kernel. It further separates itself through secure container deployment practices, utilizing SELinux mandatory access control and TPM-backed integri

Kata Containers is an OCI container runtime that launches containers inside lightweight virtual machines to combine hardware-level isolation with container operational speed. It functions as a hardware-isolated container engine and lightweight VM hypervisor, providing a virtual machine monitor interface that abstracts multiple hypervisors to optimize for performance or specific hardware emulation. The project distinguishes itself through a confidential computing runtime that leverages hardware-backed trusted execution environments, such as Intel TDX and AMD SEV-SNP, to protect data in use. It

runV is a hypervisor-based runtime for OCI.