3X-UI is the most popular open-source Xray management panel, providing a full-featured web interface for deploying and monitoring proxy and VPN protocols on Linux servers. The Go backend manages Xray-core instances supporting VLESS, VMess, Trojan, Shadowsocks, WireGuard, Hysteria2, HTTP, SOCKS, Dokodemo-door, and TUN inbounds across TCP, mKCP, WebSocket, gRPC, HTTPUpgrade, and XHTTP transports secured with TLS, XTLS Vision, and REALITY. The Clients page tracks each user with individual traffic quotas, expiration dates, concurrent connection limits, and live online status indicators, while one-click share links, QR codes, and a built-in subscription server distribute configurations in multiple output formats. The multi-node architecture manages and scales deployments across multiple servers from a single panel instance. The Panel Settings page configures listen address, port, URI path, session duration, trusted proxy CIDRs, authentication, and Telegram bot integration for remote monitoring and management alerts. Outbound routing supports WARP, NordVPN, custom rules, load balancers, and proxy chaining. Xray Configs provides template-level control over the core configuration, while the API Docs page exposes a complete RESTful API with in-panel Swagger documentation. Data persists in SQLite by default or PostgreSQL for larger deployments, with database export and import from the panel. Fail2ban integration enforces per-client IP limits. On RepoCloud, deploy 3X-UI on a dedicated VPS with Docker, root SSH access, and complete control over your proxy infrastructure, all under the GPL-3.0 license.

Starred by over 6,500 users on GitHub and trusted by organizations including Toyota, CTFd has been the leading open-source platform for hosting cybersecurity competitions since 2015, providing everything needed to run professional Capture The Flag events through a clean web-based administration panel without touching a database query. The framework supports both individual and team-based competitions with automatic tie resolution, configurable score freezing, and scoregraphs comparing the top teams with detailed progress tracking. Challenge creation offers static and regex-based flags, dynamic scoring that adjusts point values based on solve count, unlockable hints purchasable with points, file attachments uploaded to local storage or Amazon S3-compatible backends, and challenge attempt limits with automatic bruteforce protection. Version 3.8 introduced challenge logic fields controlling flag submission behavior with any, all, and team modes, integrated dynamic scoring into the standard challenge type, participant ratings and reviews on challenges, and admin-stored challenge solutions viewable after competition. The Markdown-based content management system enables custom pages for rules, FAQs, and resources, while SMTP and Mailgun integration handles email confirmation and password recovery. The plugin architecture supports custom challenge types, flag validators, and scoring algorithms, while the theme system provides complete visual customization. Import and export functionality preserves entire competition configurations for archival and reuse across events. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Backed by over 8,700 GitHub stars and OpenID Connect certification, Pocket ID delivers what enterprise identity platforms like Keycloak provide but without the configuration complexity — a passkey-only OIDC provider purpose-built for homelabs and small deployments. The core design decision is radical simplicity: no passwords exist in the system, only WebAuthn-based passkeys using hardware security keys, TouchID, FaceID, or device PINs, making phishing attacks structurally impossible rather than merely discouraged. The Go backend built on the Gin framework serves a compiled SvelteKit frontend as static assets, running as a single Docker container with SQLite as the default database and optional PostgreSQL for larger deployments. User management supports manual creation, signup links, and open registration, with group-based access control that restricts which OIDC clients each group can access and attaches custom claims for downstream role mapping. LDAP synchronization pulls users and groups from OpenLDAP or Active Directory, while SCIM support enables automated provisioning from compatible identity sources. Federated client credentials handle machine-to-machine authentication for service-to-service communication patterns. The audit system logs every authentication event with GeoIP enrichment, sends email notifications for sign-ins from unknown devices, and provides one-time login codes for accessing accounts from devices without passkey support. TLS with HTTP/2 is built in, PKCE adds code exchange protection, and OpenTelemetry provides tracing and metrics integration. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSD 2-Clause licensed.

The first container registry to reach CNCF graduated status with over 29,000 GitHub stars since VMware open-sourced it in 2016, Harbor transforms the basic Docker Distribution into a hardened enterprise registry with vulnerability scanning, supply chain signing, multi-datacenter replication, and project-level access control out of the box. Trivy scans every pushed image against the NVD, GitHub Advisory Database, and distribution-specific vulnerability feeds, with scan-on-push policies that block deployment of images exceeding configurable severity thresholds. Artifact signing through Cosign keyless signatures and Notation enforces content trust policies ensuring only cryptographically verified images reach production clusters. Policy-based replication synchronizes images and Helm charts between Harbor instances across multiple datacenters using repository, tag, and label filters with automatic retry and bandwidth throttling — enabling hybrid-cloud and disaster-recovery topologies. The RBAC model isolates projects with per-project quotas, robot accounts for CI/CD automation, webhook notifications, and audit logging that tracks every pull, push, delete, and configuration change. LDAP, Active Directory, and OIDC authentication integrate with existing identity providers, while the proxy cache transparently caches images from Docker Hub, Quay, and other upstream registries to reduce pull latency and rate-limit exposure. The RESTful API with embedded Swagger UI, tag retention policies, garbage collection scheduling, and immutable artifact rules complete the lifecycle management. Deploy via Docker Compose or Helm Chart on Kubernetes. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

The Bitwarden server, reimplemented in Rust: Vaultwarden (formerly bitwarden_rs) is the unofficial lightweight edition. It speaks the same wire protocol as the official server, so every official Bitwarden client - browser extensions, iOS, Android, desktop, and the bw CLI - connects without modification, while the server itself runs as a single container against SQLite (or MySQL/MariaDB/PostgreSQL) instead of the official multi-container stack that wants gigabytes of RAM. Features Bitwarden gates behind paid tiers ship free: organizations with collections, groups, member roles, and policies; TOTP code storage; file attachments; Bitwarden Send; Emergency Access; event logs; and admin password reset. Two-factor options cover authenticator apps, email, FIDO2 WebAuthn, YubiKey, and Duo, and OIDC-based SSO landed natively in v1.35.0. Zero-knowledge encryption is unchanged - vault data is encrypted client-side and the master password never reaches the server. Attachments and Sends store on local disk or S3-compatible backends, an admin panel manages users and server settings, and backup is copying one data directory. Suited to individuals and teams up to roughly 50 users.

Trusted by over seven million developers worldwide with 310+ contributors and more than 10,600 GitHub stars since 2011, SonarQube has become the industry standard for automated code review and continuous code quality inspection. The platform performs deep static analysis across Java, JavaScript, TypeScript, Python, C#, C++, PHP, Kotlin, Go, Ruby, Swift, and 30+ additional languages, detecting bugs that cause runtime failures, security vulnerabilities exploitable by attackers, security hotspots requiring manual review, code smells degrading maintainability, and code duplications increasing technical debt. Quality Gates define pass-fail thresholds on metrics like coverage, duplications, reliability rating, and security rating, failing CI/CD pipelines when new code introduces issues below organizational standards. Pull request analysis decorates GitHub, GitLab, Bitbucket, and Azure DevOps merge requests with inline issue annotations and overall quality summaries before merging. Built-in quality profiles provide curated rule sets per language following the Sonar Way methodology, with dedicated profiles for AI-generated code that target patterns commonly introduced by agentic coding workflows. Infrastructure-as-Code analysis covers Terraform, Kubernetes, Docker, Ansible, CloudFormation, and Helm charts with supply-chain security rules for CI/CD pipelines. The companion IDE plugin delivers real-time analysis with quick-fix guidance directly in VS Code, IntelliJ, and Eclipse. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. LGPL-3.0 licensed.

GCHQ open-sourced its "Cyber Swiss Army Knife", and CyberChef became the web app security analysts, incident responders, and CTF players reach for when data needs decoding, decrypting, or dissecting. Its interface is four panes: paste or drag input (files up to 2GB), search a categorized library of hundreds of operations, drag them into a recipe with arguments, and read the output. Operations span Base64, hex, and XOR encoding; AES, DES, and Blowfish encryption; classical ciphers from Caesar to Railfence; hashes and checksums; compression; regex and string extraction of IPs, domains, and URLs; timestamp conversion; and parsers for IPv6, X.509 certificates, and more. Recipes chain arbitrarily - convert from a hexdump then decompress, decrypt AES pulling the IV from the cipher stream, or let the Magic operation auto-detect several layers of nested encoding. Auto Bake re-runs the recipe live as input or arguments change, Step executes one operation at a time for debugging, and flow control (forks, subsections, registers) applies different operations to different parts of the data. Recipes save to files or share as URLs encoding the full pipeline. Crucially, CyberChef is entirely client-side JavaScript - nothing uploads anywhere - and self-hosting guarantees an unmodified copy inside your own network, where malware artifacts belong.

With over 34,000 GitHub stars and backing from a well-funded engineering team, Tailscale has fundamentally simplified how developers and system administrators think about secure networking. The client daemon establishes WireGuard tunnels directly between devices using sophisticated NAT traversal techniques, achieving direct peer-to-peer connections in the vast majority of network configurations without requiring port forwarding, firewall rules, or VPN concentrators. When direct connections prove impossible due to restrictive network environments, DERP relay servers provide encrypted fallback paths. MagicDNS assigns human-readable hostnames to every device on the network, eliminating the need to remember IP addresses across a tailnet. Subnet routing allows nodes to advertise access to entire local networks, enabling remote access to office resources, home labs, or cloud VPCs through a single gateway node. Exit node functionality routes all internet traffic through a designated device for privacy protection or geographic flexibility. Access control lists define granular policies for which devices and users can communicate with which services, enforced cryptographically at the network layer. The authentication layer integrates with identity providers including Google, Microsoft, GitHub, Apple, and OIDC-compliant systems for single sign-on access. Taildrop enables direct encrypted file transfers between devices without cloud intermediaries. The tailscale CLI provides complete network management from the terminal including status monitoring, route advertisement, and node configuration. Running Tailscale on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console provides a permanent, always-on node in your mesh network. BSD-3-Clause licensed with an active open-source community.

With 13,800+ GitHub stars and active releases through 2026, Casdoor is the open-source identity platform that ships OAuth 2.0, OIDC, SAML 2.0, CAS, LDAP, SCIM 2.0, WebAuthn passkeys, TOTP multi-factor authentication, and Face ID biometric login in a single Go binary with a React web console — covering every authentication protocol your organization will ever need. Social login connects 50+ identity providers including Google, GitHub, Microsoft Azure AD, Facebook, WeChat, DingTalk, Apple, Twitter, and LinkedIn without custom code. The AI-first architecture includes a Model Context Protocol gateway for AI agent authentication and Agent-to-Agent protocol support for securing LLM-powered workflows. Built-in Casbin integration delivers authorization primitives beyond basic RBAC: attribute-based access control, relationship-based access control, and custom policy models through a unified engine. The organization-scoped multi-tenancy model isolates users, applications, and identity providers per tenant with customizable login pages, branding, and SMTP configuration. SCIM 2.0 endpoints automate user provisioning from HR systems and Active Directory. Official SDKs for Go, Java, Node.js, Python, and PHP accelerate application integration. The RESTful API exposes every resource for programmatic management. Comprehensive audit logs record authentication events and administrative actions. Deploy via Docker Compose with MySQL or PostgreSQL, the all-in-one SQLite Docker image for quick trials, or the official Kubernetes Helm chart for production clusters. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

2FAuth generates TOTP, HOTP, and Steam Guard codes from any web browser, freeing your two-factor authentication from dependence on a single smartphone or app. Lose your phone, switch devices, or sit at a desktop computer, and your 2FA codes remain accessible through the web interface. The Laravel and Vue.js application stores account secrets in an encrypted SQLite database that backs up as a single file. Adding accounts works through camera-based QR scanning or manual secret key entry for services that only provide text codes. Group organization with drag-and-drop sorting keeps large collections navigable, categorized however you prefer. WebAuthn authentication with FIDO2 hardware keys protects vault access with phishing-resistant passwordless login, meaning the tool that secures your accounts is itself secured by the strongest available method. Automatic screen lock triggers after configurable idle time, and OTP obfuscation dots out generated codes until you tap to reveal them, preventing shoulder surfing in shared spaces. The REST API enables browser extensions and external applications to request codes programmatically. Import compatibility with Google Authenticator, Aegis, and 2FAS ensures painless migration without re-enrolling every account from scratch. PWA installation places 2FAuth on your device home screen for native-app-like instant access. Runs on a dedicated RepoCloud VPS with guaranteed resources and full root SSH access. AGPL-3.0 licensed.

Engineers who have outgrown Duplicati or rsync scripts tend to appreciate Kopia's design: encrypted, compressed, content-deduplicated snapshots in Go, stored in a repository on any storage you control - S3, Google Cloud Storage, Azure Blob, Backblaze B2, SFTP, WebDAV, or a plain filesystem. Encryption is mandatory and end-to-end: every block is encrypted client-side with AES-256-GCM or ChaCha20-Poly1305 using keys derived from your repository password, and even file names never leave the machine in plaintext. Blocks are packed into 20-40 MB blobs with random names, so the storage provider learns nothing about content or structure. Deduplication is automatic and content-based - identical data across files, snapshots, and even multiple machines backing up to the same repository is stored once. Policies govern everything per-directory: compression choice, retention (hourly through annual), scheduling, and ignore rules. Incremental snapshots are point-in-time records you can mount and browse like a filesystem. This deployment runs the Kopia repository server with its web UI, centralizing backups from multiple client machines over an authenticated API - each client connects with the server URL and certificate fingerprint, and users only see their own snapshots. Error correction, high-latency-tolerant caching, and both CLI and GUI round it out.

With nearly 3,000 GitHub stars and active development since 2014 through version 14.2.0, Yopass eliminates the universal bad habit of sharing passwords and API keys through Slack messages, email threads, and ticket systems by encrypting secrets entirely in the browser using OpenPGP before anything reaches the server. The Go backend stores only ciphertext — it never sees plaintext — while the React frontend handles all encryption and decryption client-side, generating one-time URLs that self-destruct after a single viewing or when the configured expiration of one hour, one day, or one week passes. File upload support streams encrypted files with configurable size limits, and optional custom password protection adds a second encryption layer beyond the URL-embedded key. The server supports Redis or Memcached as storage backends with automatic key expiration, deploying via Docker Compose in under five minutes or as Kubernetes manifests for production environments. Built-in TLS support works alongside reverse proxy configurations for Nginx, Caddy, and Traefik with automatic Let's Encrypt certificate provisioning. Prometheus metrics expose HTTP request counts, latency histograms, and secret lifecycle counters for Grafana dashboard integration and alerting. Read-only mode enables split-instance deployments separating secret creation from retrieval across different network zones. Multi-language support localizes the interface for international teams. The open-source core under Apache 2.0 provides full self-hosted functionality with no account management required. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.

With over 36,000 GitHub stars and adoption by organizations including Adobe, Shopify, and Roblox, HashiCorp Vault is the industry-standard platform for secrets management, encryption services, and privileged access control across hybrid and multi-cloud infrastructure. The key/value secrets engine stores arbitrary secrets with full versioning, soft-delete, and metadata tracking, while dynamic secrets engines generate on-demand, short-lived credentials for AWS, Azure, GCP, databases including PostgreSQL, MySQL, MongoDB, and MSSQL, and SSH access with automatic revocation after configurable lease periods. The PKI secrets engine dynamically issues X.509 certificates on demand with automatic rotation and ACME protocol support, eliminating manual certificate management workflows entirely. Encryption as a service through the transit secrets engine lets applications encrypt, decrypt, sign, verify, and generate HMACs without managing cryptographic keys directly, supporting AES-GCM-256, ChaCha20-Poly1305, RSA-2048/4096, ECDSA-P256/P384, and ED25519 algorithms. Authentication integrates with LDAP, OIDC/OAuth2, SAML, AppRole for machine-to-machine access, Kubernetes service accounts, AWS IAM, Azure Active Directory, and GitHub tokens. Fine-grained ACL policies use path-based rules with glob patterns and sentinel policies for programmatic enforcement. The integrated Raft storage backend provides high-availability clustering without external dependencies, while alternative backends include Consul, S3, DynamoDB, PostgreSQL, and MySQL. The built-in web UI provides a visual interface for browsing secrets, managing policies, configuring auth methods, and monitoring cluster health. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSL 1.1 licensed.

With over 24,000 GitHub stars and a rapidly growing community of self-hosters, authentik delivers enterprise-grade identity management that replaces commercial solutions like Okta and Auth0 with a fully self-hosted platform requiring no per-user licensing fees. The platform serves as a unified identity provider supporting SAML 2.0, OAuth 2.0 and OpenID Connect, LDAP for legacy application compatibility, SCIM 2.0 for automated user provisioning, and RADIUS for network device authentication. The visual flow designer enables administrators to create custom authentication workflows combining password verification, multi-factor authentication with TOTP, WebAuthn, and SMS codes, email verification, captcha challenges, and conditional logic based on user attributes or device context. The forward-auth and reverse proxy integration works seamlessly with Traefik, Nginx, Caddy, and Envoy to protect applications that lack built-in authentication. User enrollment flows support self-registration with configurable approval workflows, invitation links, and automatic group assignment. The LDAP outpost exposes user and group data to legacy applications requiring LDAP bind authentication, while the SCIM provider automates user lifecycle management with downstream applications. Multi-tenancy support through brands allows a single authentik instance to serve multiple organizations with independent domains, branding, and authentication policies. The admin interface provides comprehensive user management, group hierarchy, application catalog, event logging with GeoIP enrichment, and system health monitoring. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Licensed under a source-available license with an open-source community edition.

Security-conscious IT departments pick Passbolt for its cryptography: every user holds an OpenPGP key pair, and shared credentials are encrypted individually to each recipient's public key - real end-to-end encryption, not a vault password handed around. All crypto runs client-side in the mandatory browser extension (distributed and signed through the Chrome and Firefox stores, deliberately separating the crypto code from the server that stores ciphertext); private keys and passphrases never touch your instance, and the server admin cannot read a single secret. Authentication uses the challenge-based GpgAuth protocol, secrets are digitally signed to verify sender integrity, and metadata encryption extends protection to resource names and URLs. Day to day it behaves like a polished commercial manager: auto-fill and auto-save in forms, strong password generation, anti-phishing protection, TOTP storage, folder hierarchies shared per-user or per-group with fine-grained permissions and instant cryptographic revocation. Native iOS, Android, and desktop apps ship alongside a JSON API, CLI, and SDKs for CI/CD secret retrieval and rotation. The PHP server runs on MariaDB and is AGPL-licensed open source - including the paid tiers' codebase - with published security audits.

Encrypted, incremental, compressed backups on storage you already have - Amazon S3, Backblaze B2, Google Drive, Azure, OneDrive, Dropbox, MEGA, Storj, WebDAV, SFTP, FTP, SMB, or a plain local disk - is what the MIT-licensed Duplicati has quietly done for years. Its security model is Trust No One: every block is encrypted with AES-256 (or a local GPG instance) before leaving the machine, and the passphrase never travels, so the storage provider holds only ciphertext. The block-based storage engine gives the best of both backup worlds: after one initial full backup, only changed data blocks upload - modify a tiny part of a huge file and only that part transfers - yet every backup version restores like a full backup in a single operation, with no incremental chains to replay. Deduplication and compression keep remote storage growth slow even across years of versions. A web interface manages everything: the built-in scheduler keeps backups current automatically, flexible filters select folders, file types, or custom patterns, retention policies prune old versions, and an integrated updater flags new releases. On compatible object-lock backends, immutable (WORM) storage protects backup data from ransomware that reaches the credentials. Runs on Windows, macOS, and Linux, free even for commercial use.

Authentication that lives inside your application rather than behind a redirect to an external identity provider - SuperTokens takes a fundamentally different architecture from Auth0 and AWS Cognito. Three tiers make that work - frontend SDKs (React, Angular, Vue, vanilla JS, React Native) render overridable login UI and manage tokens; backend SDKs (Node.js, Python, Go) expose auth endpoints on your own API domain; and SuperTokens Core, the piece you host here, is the stateless HTTP service handling core auth logic, password hashing, token signing, and database operations against PostgreSQL. The recipe system keeps features decoupled: use email/password, social login, passwordless (magic links, OTP), phone-password, multi-factor authentication (TOTP, WebAuthn), user roles, and microservice auth - individually or combined; you can even use SuperTokens purely for session management alongside another login provider. Sessions are where it shines: rotating refresh tokens with theft detection, automatic access-token refresh, CSRF protection, and secure cookie handling out of the box - the details that become vulnerabilities when hand-rolled. Verification happens locally in your backend via cached JWT signing keys, so the Core stays off the hot path. Self-hosted means no user limits, free forever, with all user data in your database. Apache-licensed.

Powering authentication for over 15,000 GitHub stargazers and production deployments across startups and enterprises alike, SuperTokens delivers the complete login infrastructure that Auth0, Firebase Auth, and AWS Cognito charge premium prices for — entirely open source under Apache 2.0 with no per-user limits. The Java-based core service runs as a lightweight HTTP microservice that connects to PostgreSQL or MySQL and handles email-password login, passwordless magic links and OTP via email or SMS, social OAuth with Google, GitHub, Facebook, Apple, and any custom OIDC provider, phone-password authentication, and time-based one-time password multi-factor authentication. Session management uses rotating refresh tokens with anti-CSRF and anti-session-fixation protections, verifying tokens locally in your backend SDK without network round-trips to the core. Frontend SDKs for React, React Native, Angular, Vue, and vanilla JavaScript provide pre-built UI components for login, signup, email verification, and password reset flows, all customizable through an override system that lets you add pre- and post-API logic, custom hooks, and user event handlers. The built-in user management dashboard enables administrators to view users, reset passwords, revoke sessions, modify roles, and manage email verification status. Multi-tenancy and organization support powers B2B SaaS applications with tenant-level authentication configuration and Enterprise SSO via SAML and OIDC. Migration tools support bulk importing millions of existing password hashes, TOTP secrets, and role mappings. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.