Open-source alternatives to Hyperd

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

Podman is a container engine designed for managing containerized applications and images without the need for a persistent background daemon. By utilizing a fork-exec process model, it executes container management commands as direct child processes of the host system, ensuring that container lifecycles are handled through standard host-level process control. The project distinguishes itself through a focus on rootless security and cross-platform compatibility. It employs user namespace mapping to allow unprivileged users to manage isolated workloads without requiring administrative system ac

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

Spin is a WebAssembly serverless framework and development toolchain for building and running portable microservices. It functions as an event-driven orchestrator and runtime that executes WebAssembly components, allowing developers to map HTTP requests, Redis messages, and cron schedules to specific modules. The project distinguishes itself by implementing a Wasm-based AI inference gateway, enabling components to perform model inference and generate text embeddings. It utilizes the WebAssembly Component Model and WASI for language-agnostic composition and portable host interfacing, while emp

firecracker-containerd enables containerd to manage containers as Firecracker microVMs

img is a collection of toolsets for building, managing, and manipulating OCI compliant container images. It functions as an image build tool and registry client, providing the capabilities to create images from configuration files, push and pull images to remote registries, and extract image layers into root filesystems or archives. The project distinguishes itself through support for multi-platform builds using hardware emulators and the ability to perform unprivileged container builds via namespace-based process isolation and user ID mapping. It also includes a cross-platform binary compile

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

Agones is a Kubernetes game server orchestrator designed for deploying, scaling, and managing dedicated multiplayer game server processes across a distributed cluster. It provides the core infrastructure needed to provision individual or grouped server processes to support real-time multiplayer gaming sessions. The system includes a fleet manager to automate the lifecycle of server groups based on player demand and a health monitor to track the connectivity and operational status of active processes. It integrates with cluster autoscalers to synchronize server resource requirements with cloud

A multi-sandbox container runtime that provides cloud-native, all-scenario multiple sandbox container solutions.

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

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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

Secure sandbox runtime for AI agents

Docker-compatible container CLI built on Apple's Containerization framework. Same commands, same flags — mocker run, ps, stop, build, compose, stats — all working on macOS 26.

wasmCloud is an open source Cloud Native Computing Foundation (CNCF) project that enables teams to build, manage, and scale polyglot apps across any cloud, K8s, or edge.