Open-source alternatives to Us Den

Find security vulnerabilities, compliance issues, and infrastructure misconfigurations early in the development cycle of your infrastructure-as-code with KICS by Checkmarx.

Lynis is an automated security auditing and system hardening framework designed for UNIX-based operating systems. It functions as a command-line utility that inspects local system configurations to identify security vulnerabilities, configuration weaknesses, and compliance gaps. By executing a series of modular tests, the tool generates actionable reports and remediation suggestions to assist in strengthening system defenses. The project distinguishes itself through a highly modular architecture that relies on shell-script-based execution and native system inspection. Users can define custom

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

Facilitates running Wasm / WASI workloads managed by containerd

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

Secure your Docker builds against supply chain attacks — restrict outbound network access to only the domains you allow

ThreatMapper is a cloud native application protection platform and infrastructure security scanner. It functions as a vulnerability management system and cloud workload telemetry collector designed to monitor workloads and detect security risks across cloud and container environments. The platform distinguishes itself through a network traffic visualizer that uses machine learning to classify communication patterns and a graph-based attack mapping system to identify high-risk paths between vulnerabilities and network dependencies. Its broader capabilities cover cloud infrastructure complianc

This project is a security compliance tool and configuration auditor designed to evaluate Docker deployments against industry security benchmarks. It functions as a script-based scanner that identifies misconfigurations and vulnerabilities within both the host operating system and container settings. The tool specifically implements the Center for Internet Security standards for Docker to verify host and container configurations. It enables a hardening workflow by comparing system states against these standards to identify security gaps and document compliance status. The audit engine suppor

Static analysis from configs → Kubernetes NetworkPolicies in seconds

Fail2ban is an intrusion prevention system that monitors system log files to detect malicious activity and automatically enforce security policies. By parsing log data in real time, the tool identifies patterns of unauthorized access or repeated authentication failures and responds by dynamically updating network access control lists to restrict offending sources. The software functions as a firewall automation tool that maintains stateful tracking of suspicious behavior across various network services. It utilizes a regex-driven pattern matching engine to identify specific attack signatures,

Falco is an eBPF runtime security monitor and cloud native detection engine that identifies abnormal behavior and security threats across hosts and containers. It functions as a Linux kernel event auditor, capturing system calls and kernel events in real-time to detect malicious activity. The system distinguishes itself through a rule-based threat detection model that evaluates system activity against a library of community-maintained rules and custom security definitions. It enriches raw kernel events with container and Kubernetes metadata to provide observability into isolated environments

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

Container Explorer (built as ce) is a standalone Go utility for exploring, analyzing, and performing forensics on container runtimes (such as containerd, Docker, and Podman).

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

gopass is a terminal-based password manager and GPG secret store used for generating, storing, and retrieving encrypted credentials. It functions as a collaborative secret manager that encrypts data using GPG or age and synchronizes it across devices and teams using Git. The system distinguishes itself by treating version control repositories as the primary storage backend, enabling secure secret sharing and version history for credentials. It utilizes a hierarchical directory structure to organize secrets on the filesystem and supports multi-store mounting to combine multiple independent rep

Client for PPP+TLS VPN tunnel services