Open-source alternatives to Youki

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

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

Isolate is a low-level sandbox designed to execute untrusted programs within a strictly controlled environment. It functions as a process isolation engine that prevents potentially harmful code from interacting with or damaging the host operating system. The tool leverages Linux kernel primitives, including namespaces and control groups, to partition system resources and enforce hardware usage boundaries. By applying filesystem virtualization and system call filtering, it restricts the visibility and interaction of a process with the host, ensuring that untrusted applications operate only wit

Firejail is a Linux application sandbox and kernel security wrapper that isolates untrusted applications from the host system. It uses kernel namespaces and seccomp filters to restrict filesystem access, drop kernel capabilities, and limit the system attack surface. The project is distinguished by its use of predefined security profiles to automatically apply filesystem restrictions and syscall limits based on the executable being launched. It provides specialized isolation for portable packages such as AppImages and implements X11 display isolation via proxy servers to prevent keyboard loggi

Bubblewrap is a Linux sandbox runner that creates lightweight, isolated execution environments for running untrusted applications. It combines Linux user, mount, network, PID, and UTS namespaces with seccomp-BPF system call filtering to restrict filesystem, network, process, and inter-process communication access. The project provides comprehensive process isolation by giving each sandbox its own private tmpfs root with selective bind-mounts, a separate network stack containing only a loopback interface, an independent process ID space, and remapped user and group identifiers. It applies secc

Bubblewrap is an unprivileged sandbox execution utility for Linux that isolates processes from the host system. It creates secure environments by leveraging Linux namespaces to separate system resources, including network, PID, and IPC stacks. The project distinguishes itself by enabling the execution of untrusted software without requiring root privileges on the host machine. It prevents privilege escalation by disabling the execution of setuid binaries and uses user identity mapping to isolate process permissions from the host operating system. The tool manages a comprehensive security sur

Libpod is a container management library for running and controlling the lifecycle of Open Container Initiative compliant containers and images across different storage backends. It provides a programmatic interface for the remote control and automation of container environments. The project enables the coordination of multiple containers into pods that share network namespaces and other shared resources. It supports rootless container execution by using user namespaces to launch containers without administrative privileges. The library covers a broad range of system operations, including im

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

LXC is an OS-level virtualization framework and Linux container manager used to run multiple isolated Linux systems on a single host. It functions as a kernel namespace orchestrator and unprivileged container runtime, allowing for the creation and management of system containers without the overhead of a hypervisor. The project provides unprivileged container execution by mapping container root users to unprivileged host users to prevent host system access. It ensures security through system call filtering and root user isolation, enabling containers to run without requiring host root privile

This project is a collection of curated and standardized Docker base images that serve as reliable starting points for building containerized applications. It functions as an OCI container image repository and a build template library, providing a central source of truth for images that adhere to Open Container Initiative standards for portability. The project utilizes an automated image lifecycle pipeline to build, tag, and push images, ensuring that dependencies remain current and security patches are applied. It specifically supports cross-platform distribution by providing a multi-archite

This project is a Docker educational resource and a collection of practical examples designed for learning containerization technologies. It serves as a guide for understanding container fundamentals, including the creation and management of custom images and the use of registries. The repository provides specialized references for container security hardening, such as managing kernel privileges and implementing supply chain security. It also includes tutorials for multi-container orchestration and a DevOps guide focused on CI/CD automation and image optimization. The material covers a broad

dockerlabs is a collection of educational labs and technical tutorials designed to teach the fundamentals of containerization and microservice architecture. It provides instructional material and hands-on exercises covering image optimization, security training, infrastructure setup, and cluster orchestration. The project features specific courses and guides focused on reducing image size through multi-stage builds, securing workloads via vulnerability scanning and encrypted networks, and deploying multi-node clusters with high availability using Swarm orchestration. The materials cover a br

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

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

Docker is an OCI container engine and runtime orchestrator used to build, run, and manage isolated applications. It functions as a container image builder for creating portable snapshots of applications and a registry manager for storing, versioning, and distributing those images across environments. The platform provides a centralized daemon to control the creation, execution, and termination of containerized workloads. It allows for the assembly of modular container systems by combining build tools, registries, and runtimes. Its core capabilities cover container image creation, registry ad

rkt is a secure Linux container engine and pod-native container manager. It provides a composable execution environment for launching and managing isolated application containers on Linux, serving as a runtime designed around open industry standards for image formats and networking interfaces. The system is distinguished by a pod-native execution model that groups multiple containers and shared resources into single, self-contained units. It utilizes pluggable execution engines to provide secure isolation, including the use of hardware-based virtualization to create security boundaries betwee

Incus is a unified orchestration platform for managing system containers, OCI application containers, and virtual machines through a single control plane. It brings together cluster infrastructure management, secure multi-tenancy, software-defined networking, and pluggable storage backend orchestration into one cohesive system exposed via a full REST API and command-line interface. What distinguishes Incus is its ability to run multiple instance types side by side—full Linux system containers, OCI application containers, and QEMU virtual machines—all managed with consistent tooling. Networkin

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

Flatpak is a sandboxed application framework and standardized packaging format for Linux desktop applications. It functions as a distribution system that allows a single application bundle to run consistently across multiple Linux operating systems without requiring per-distribution builds. The project provides a runtime dependency manager that bundles specific library versions or shared runtimes to create predictable execution environments. It includes a sandbox permission manager to control application access to system hardware and resources, ensuring security and consistent behavior betwee

Bocker is a minimal container management tool written in Bash that implements core container functionality using Linux namespaces and control groups. It serves as a Linux container manager capable of starting and managing isolated processes and images through low-level kernel features. The project includes an OCI image tool for pulling, saving, and building container images compatible with industry standards. It further integrates a cgroup resource controller to restrict CPU and memory consumption for isolated processes. The tool covers the full container lifecycle, including process isolati

proot-distro is a rootless container runtime and Linux distribution manager that allows users to install and run isolated guest environments without requiring administrative root privileges. It utilizes PRoot to simulate root access and filesystem redirection, enabling the deployment of full Linux distributions in a non-root space. The project functions as an OCI container image handler, capable of building, pulling, and pushing OCI-compatible images and manifests. It further serves as a cross-architecture execution layer, utilizing user-mode emulation to run binaries and containers built for

Wasmtime is a WebAssembly runtime and sandboxed bytecode executor designed to run WebAssembly bytecode on a host system. It functions as an embeddable engine that integrates into applications through native APIs and language-specific bindings, as well as a standalone execution environment accessible via a command line interface. It is a WASI compatible runtime, implementing the WebAssembly System Interface to provide portable access to system resources. The engine utilizes a JIT compilation model to translate intermediate representation into optimized machine code for various CPU architecture

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

Lunatic is a WebAssembly runtime and concurrent process manager that implements an Erlang-inspired model of lightweight concurrency and fault tolerance. It functions as a distributed actor system where isolated processes communicate via message passing across a network of linked nodes. The system utilizes a WebAssembly sandbox environment to isolate memory and restrict system call permissions for each individual process. This capability-based security model ensures that processes are sandboxed to safely execute untrusted code. The platform provides a fault-tolerant supervision tree for hiera

cve-rs is a memory safety testing framework and vulnerability simulator designed to recreate buffer overflows and segmentation faults. It provides a set of safe memory primitives and a WebAssembly-based security sandbox to evaluate how programs handle unsafe memory access within an isolated execution environment. The project replaces raw pointer manipulation and type transmutation with functional alternatives, allowing for the simulation of memory-unsafe operations. It enables the reinterpretation of data types through memory representation manipulation rather than unsafe casting to study the

Dify-sandbox is a secure runtime environment designed for the execution of untrusted code snippets. It functions as a containerized sandbox that isolates processes from the host operating system, ensuring that arbitrary scripts can be run without granting them unauthorized access to sensitive data or critical system resources. The project distinguishes itself through a multi-layered security approach that combines kernel-level isolation with strict resource management. By utilizing Linux namespaces and container-based process isolation, it partitions system resources to maintain visibility bo