The movie half of the *arr stack: Radarr is a .NET collection manager that automates acquiring films for Usenet and BitTorrent users the way Sonarr does for TV. Add a movie once and Radarr handles the rest: it monitors indexers and RSS feeds, grabs a matching release the moment one appears, sends it to SABnzbd, NZBGet, qBittorrent, Deluge, Transmission, rTorrent, or another connected download client, then imports, sorts, and renames the file into your library structure. Quality profiles are the control surface - define allowed resolutions and a cutoff, and Radarr keeps upgrading files automatically, replacing a DVD rip when a Blu-ray release lands. Custom formats go further, scoring releases by codec, HDR metadata, release group, streaming source, or arbitrary regex so the copy you want always wins the pick. Failed downloads retry with another release automatically; a manual search shows every candidate and explains why one was skipped. Release parsing recognizes director's cuts, special editions, AKA titles, and hardcoded subs. Plex and Kodi integration handles notifications, library refreshes, and metadata like posters, trailers, and subtitles, and a calendar view tracks upcoming releases. It pairs naturally with Jellyseerr for request management and shares its API conventions with the whole *arr ecosystem.

With nearly 14,000 GitHub stars and over 200 releases, Semaphore UI has established itself as the lightweight yet powerful alternative to enterprise automation platforms like Ansible AWX and Jenkins. Unlike AWX's heavyweight Kubernetes-dependent architecture, Semaphore ships as a single Go binary with zero external runtime dependencies — install it, run setup, and you have a production-ready automation server in minutes. The platform natively orchestrates Ansible playbooks, Terraform and OpenTofu infrastructure code, Terragrunt configurations, PowerShell scripts, Bash commands, and Python automation, all from a clean Vue.js web interface that displays task history, execution logs, and scheduling status at a glance. Semaphore supports concurrent task execution across multiple servers using distributed project runners, enabling horizontal scaling of automation workloads without complex clustering. The built-in inventory management system handles both static and dynamic inventory sources, while four-level RBAC (Owner, Manager, Task Runner, Guest) provides granular access control for team environments. Notifications flow to Slack, Microsoft Teams, Telegram, email, Rocket.Chat, and Gotify, keeping operators informed of failed tasks and deployment status. Integration with HashiCorp Vault secures sensitive credentials, and the comprehensive REST API with built-in Swagger documentation enables programmatic automation. Deploy via Docker Compose, Helm chart for Kubernetes, or native packages for Debian, Ubuntu, and RHEL-based distributions. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

With over 6,500 GitHub stars, HolaOS bills itself as an "open agent computer" that reimagines the traditional operating system as a shared workspace where humans and AI agents collaborate across files, browsers, and 100+ integrated tools simultaneously. Unlike chat-only interfaces, HolaOS places live application UIs—Notion-style editors, browsers, custom workspace apps—side by side with the agent conversation, so operators always see what agents are doing and can intervene at any moment. The persistent memory system stores workspace knowledge locally as Markdown files and embedded vectors via SQLite vec, enabling RAG-powered recall that survives session boundaries without the typical context window bloat. Safe Session Compaction reserves roughly 70% of the model context window for fresh reasoning while folding older history into structured checkpoints that retain goals, constraints, progress, and decisions. Agents connect to Linear, GitHub, Slack, Jira, HubSpot, Gmail, and dozens more through one-click OAuth, automatically fetching relevant signals and converting scattered app data into working memory. BYOK support for Claude, GPT, and Gemini models lets operators use their own API keys at zero markup, while built-in Kimi K3 and GLM-5.2 models provide ready-to-use alternatives. Skills package reusable workflows that any agent can invoke on demand, and scheduled triggers enable autonomous digests, monitors, and reports. The runtime supports independent server deployment alongside the desktop client. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Modified Apache 2.0 licensed.

Scheduling infrastructure, not just a booking page - Cal.com is the leading open-source scheduling platform. Share a link, attendees pick a slot, and real-time sync against Google Calendar, Outlook, and CalDAV prevents double-booking. Beyond the basics it covers team workflows: round-robin distribution, collective availability across multiple hosts, recurring meetings, and routing forms that ask bookers questions and send them to the right team member - the feature sales and support teams usually pay enterprise prices for. Paid bookings run through Stripe, video calls through the built-in Cal Video (Daily.co) or Zoom and Google Meet, and an app store connects 100+ tools including HubSpot, Zapier, and n8n. The API-first architecture with webhooks and embeds makes it practical to build scheduling into your own product, white-labeled with your domain and branding. Built on Next.js and Prisma over PostgreSQL, translated into 65+ languages, with the self-hostable community codebase maintained under an open-source license.

With over 47,000 GitHub stars, Cal.diy is the fully open-source community fork of Cal.com that strips away every proprietary license gate and enterprise paywall to deliver a pure MIT-licensed scheduling platform you completely own. The booking engine supports individual event types including recurring events, seated events with capacity limits, and paid bookings through Stripe and PayPal, all backed by customizable availability schedules with date overrides, buffer times, minimum notice periods, and travel schedule support. Calendar synchronization is bidirectional across nine providers — Google Calendar, Outlook and Office 365, Apple Calendar, CalDAV, Lark, Feishu, Zoho, Exchange, and ICS feeds — so every booking automatically appears on your existing calendar while blocking conflicting slots. Video conferencing links generate automatically for Zoom, Google Meet, Microsoft Teams, Webex, Jitsi, Daily.co, Whereby, and Huddle01, eliminating manual link management. The automation layer connects through webhooks, Zapier, n8n, Make, and Pipedream to CRM platforms like HubSpot, Salesforce, and Close, messaging services including Discord, Telegram, and WhatsApp, and analytics tools such as Google Analytics 4, PostHog, and Fathom. The entire application is built on the T3 stack — Next.js for server-rendered pages, tRPC for end-to-end type-safe APIs, Prisma for PostgreSQL database access, and Tailwind CSS for the responsive interface. Unlike Cal.com's open-core model, Cal.diy requires no license key and includes no gated features. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Most wikis die of flat page-and-tag sprawl; BookStack's defining decision is enforced structure - an MIT-licensed PHP/Laravel platform (over MySQL) where content lives in a hierarchy of shelves, books, chapters, and pages, the way a physical library works. A shelf maps to a department, a book to "Engineering Runbooks," a chapter to "Database Procedures," a page to the actual document. That opinionation removes the "where does this go?" friction and keeps knowledge bases tidy as they grow. Editing works both ways: a clean WYSIWYG editor for most users, a Markdown editor with live preview for those who prefer it - switchable per page. Full-text search spans all books or scopes to one, with direct links to individual paragraphs, and include tags let you embed one page's content inside another so shared blocks update everywhere at once. Every edit creates a diffable, revertible revision. Page templates standardize recurring formats, tags add cross-cutting categorization, and built-in diagrams.net integration draws architecture diagrams in place. Authentication covers email/password plus OIDC, SAML2, LDAP, and social login; a full role and permission system locks content down per shelf, book, or page. Pages and books export to PDF, HTML, plain text, and Markdown, a REST API automates content, and the whole thing runs happily on the cheapest VPS you can find.

With 23,600 GitHub stars, 13 million monthly PyPI downloads, and 425+ contributors automating over 200 million data tasks monthly for Fortune 50 companies like Progressive Insurance and disruptors like Cash App, Prefect is the most widely deployed open-source workflow orchestration framework for Python — turning any script into a resilient production pipeline with a single @flow decorator while eliminating rigid DAG structures entirely. The durable execution engine persists task results and automatically resumes from failures without replaying expensive upstream work, guaranteeing exactly-once execution for any Python function. Event-driven automation triggers workflows from webhooks, cloud events, or state changes through a real-time event bus that detects what happens or fails to happen across your entire data platform. Work pools decouple workflow code from infrastructure, enabling seamless switching between Docker, Kubernetes, AWS ECS, Azure Container Instances, GCP Cloud Run, and serverless environments without modifying pipeline logic. Native Ray and Dask task runners extend execution across clusters for compute-intensive workloads. The self-hosted server provides a monitoring dashboard with flow run timelines, task state visualization, scheduling, and automation configuration. The third-generation engine reduces overhead by over 90 percent compared to Prefect 2, supporting batch, event-driven, interactive, and background task workflows. Deploy via Docker Compose with PostgreSQL, Redis, server, background services, and worker containers, or use official Helm charts for production 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.

With over 35,000 GitHub stars and 460 contributors, Medusa is the headless commerce framework that gives development teams full ownership of their e-commerce backend without license fees, per-transaction charges, or revenue sharing. The modular architecture ships over 18 domain modules covering products, collections, categories, inventory, pricing, carts, orders, payments, fulfillment, promotions, customers, users, API keys, and stock locations, each independently usable and replaceable. REST and GraphQL APIs expose every commerce operation to any frontend framework — official starters exist for Next.js with community options for Nuxt, Remix, and Gatsby. The React-based admin dashboard provides out-of-the-box order management, product maintenance, promotions configuration, B2B accounts, and multi-warehouse inventory, extensible via the Admin SDK for custom views and workflows. The workflow engine orchestrates long-running commerce processes like checkout, fulfillment, and returns with compensating transactions for reliability. Over 200 official and community plugins integrate Stripe, PayPal, Klarna, Algolia, Meilisearch, SendGrid, Mailchimp, Contentful, Sanity, and Klaviyo. Native multi-region and multi-currency support handles tax-inclusive pricing, region-specific payment and fulfillment providers, and localized storefronts from a single backend. Enterprises including Viessmann, Makro PRO, and INSPIRED Pet Nutrition run Medusa in production. Self-hosting deploys via Docker or directly on Node.js with PostgreSQL and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

With over 13,000 GitHub stars and active monthly releases, Mailcow delivers a production-ready mail server infrastructure through Docker Compose orchestration of twelve integrated containers. The stack pairs Postfix as the MTA handling SMTP traffic with Dovecot for IMAP and POP3 retrieval featuring the Flatcurve full-text search engine, while Rspamd provides machine-learning-powered spam filtering with Bayesian classification, DKIM signing, and ARC support. ClamAV scans attachments for malware including Office document macro analysis via Olefy, and SOGo serves as a responsive webmail client with CalDAV, CardDAV, and Microsoft ActiveSync synchronization. The admin panel manages multiple domains, per-user spam score thresholds, quarantine review, black and whitelists, temporary spam aliases, mailbox quotas, and TLS enforcement policies for both inbound and outbound messages. Security features include two-factor authentication via TOTP, WebAuthn, and Yubikey OTP, a Fail2ban-like Netfilter integration for brute-force protection, and automatic SPF, DKIM, and DMARC configuration. The ACME container handles Let's Encrypt certificate generation with DNS-01 challenge support, while Postfix TLS-Pol provides MTA-STS and DANE/TLSA resolution for encrypted transport. Built-in imapsync enables periodic migration from remote mailboxes, and the REST API allows programmatic management of all server resources. MariaDB stores user data, Redis caches configuration and sessions, and Unbound provides local DNSSEC-validating DNS resolution. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

The most feature-complete open-source alternative to Google's NotebookLM — a self-hosted research platform where you upload PDFs, videos, audio files, and web pages into organized notebooks, then chat with your content, generate multi-speaker podcasts, and run semantic search across everything without sending a single byte to Google's servers. The podcast engine supports 1-4 fully customizable speakers with backstories, personalities, and expertise profiles, generating professional audio dialogue through OpenAI, ElevenLabs, Google TTS, or completely local text-to-speech via Kokoro for maximum privacy. Content processing uses token-based chunking with RAG-powered retrieval grounded in your uploaded sources, while both full-text keyword search and semantic vector search via SurrealDB enable conceptual discovery across all notebooks. The 18+ supported AI providers include OpenAI, Anthropic, Google Gemini, Groq, Ollama, LM Studio, and more — configurable per task so you can route cheap models to summarization and powerful models to analysis. Content transformations extract insights, generate summaries, create study guides, and produce structured outputs from any source material. The MCP integration connects Open Notebook to Claude Desktop, VS Code, and other MCP clients for seamless workflow integration. A full REST API on port 5055 enables complete automation of notebook management, source upload, and podcast generation. Deploy via Docker Compose with the application container, SurrealDB v2 on RocksDB, and optional TTS containers. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

The open-source PaaS with 55,000+ GitHub stars and the largest one-click service catalog in its class — Coolify gives you the Vercel push-to-deploy workflow on a dedicated server you control. Connect a GitHub, GitLab, Bitbucket, or Gitea repository and every push builds and deploys automatically via Nixpacks, a Dockerfile, or Docker Compose, with Traefik or Caddy reverse proxying, automatic Let's Encrypt certificates, and per-branch preview deployments with their own URLs. Databases — PostgreSQL, MySQL, MariaDB, MongoDB, Redis — provision in a few clicks, and a catalog of 280+ one-click service templates covers WordPress, n8n, Grafana, MinIO, Plausible, Ollama, and more. One dashboard manages the entire server, with Docker Swarm available for clustering multiple nodes. Backups go to any S3-compatible storage with one-click restore, and a full API supports CI/CD integration. All configuration lives on your own server, so resources keep running even if you stop using Coolify — no vendor lock-in by design. Running on a dedicated VPS with guaranteed CPU, RAM, and SSD, full root access via SSH and browser console. Apache 2.0 licensed.

Deployed at thousands of enterprises across financial services, healthcare, government, and telecommunications, Apache NiFi is the industry-standard platform for building automated data pipelines through a visual drag-and-drop browser interface that requires zero coding for common integration patterns. The flow-based programming model connects over 300 built-in processors covering relational databases via ExecuteSQL and PutDatabaseRecord, Apache Kafka with PublishKafka and ConsumeKafka, HTTP endpoints through InvokeHTTP and ListenHTTP, cloud storage for AWS S3, Azure Blob, and Google Cloud Storage, SFTP/FTP file transfers, and JSON, XML, CSV, and Avro transformations. Data provenance tracking logs every routing decision, transformation, and delivery for every FlowFile, creating a searchable lineage graph from source to destination with full content replay capability for auditing and debugging. Guaranteed delivery uses configurable backpressure thresholds, prioritized queuing with latency or throughput optimization, and automatic retry with exponential backoff, ensuring no data loss even during downstream outages. The zero-leader clustering architecture distributes processing across nodes with automatic load balancing, while site-to-site protocol enables secure data transfer between NiFi instances across network boundaries. Security includes OpenID Connect and SAML 2.0 single sign-on, role-based access control with fine-grained policies per component, and TLS encryption for all communication. Custom processors can be written in Java and packaged as NAR bundles, or implemented directly in Python through the native scripting framework. 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.

Born at Brazilian media giant Globo.com, Thumbor answers imaging CDNs like Imgix and Cloudinary with an HTTP service where every image variant is just a URL. Ask for /300x200/smart/your-image.jpg and Thumbor fetches the original, crops and resizes on demand, and caches the result - one source file, unlimited renditions, no batch pre-generation pipeline. The "smart" in the URL is the signature feature: OpenCV-based face detection finds people in the frame and crops around them (no more thumbnails with severed heads), and when no faces exist, feature detection finds visually important corners and computes a weighted center of mass as the focal point. Beyond cropping, a chainable filter pipeline handles brightness, contrast, grayscale, blur, red-eye removal, rounded corners, rotation, watermarks, and format conversion with quality control - applied in order via URL segments. All common image formats work out of the box, and every layer is pluggable: loaders (HTTP, local, S3), storages and result storages (local, S3, Ceph, and community backends), engines, optimizers, filters, and even custom detectors, with the awesome-thumbor list cataloging the ecosystem. URL signing prevents abuse of your processing capacity. Integrations exist for Django, Rails, Node, WordPress, and most frameworks. MIT-licensed, battle- tested for over a decade.

Benchmarked at one million concurrent WebSocket connections and 30 million delivered messages per minute on a single server, Centrifugo is a self-hosted real-time messaging server that integrates with any backend language — Node.js, Python, Go, Ruby, PHP, Java — without requiring architectural changes to your existing application. It handles persistent connections over WebSocket, HTTP-streaming, Server-Sent Events, gRPC, and experimental WebTransport, routing messages through a channel-based PUB/SUB model with automatic reconnection recovery that replays missed messages from hot channel history. Built-in horizontal scaling operates through Redis (including Redis Cluster, AWS ElastiCache, Valkey, KeyDB, and DragonflyDB), NATS, or PostgreSQL brokers, allowing multi-node deployments without external message queues. The server provides JWT-based authentication using HMAC or RSA keys, granular channel permissions, online presence tracking showing who is currently subscribed to a channel, and an RPC proxy that forwards client calls to your backend over HTTP or gRPC. The embedded ReactJS admin web interface displays real-time connection statistics, node information, and provides an interactive API console for publishing messages, managing subscriptions, and inspecting channel history. Official client SDKs are available for JavaScript, Dart, Go, Swift, and Java, with unidirectional transports requiring no SDK at all. Centrifugo also supports delta updates to minimize bandwidth, connection event proxying, and Prometheus-compatible metrics for Grafana monitoring. 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 36,000 GitHub stars and 120 contributors with 123 releases since 2022, 1Panel has rapidly become the go-to open-source alternative to cPanel and Plesk for modern Linux server management. The platform delivers a clean Vue.js dashboard powered by a Go backend using the Gin framework, providing visual management of Docker containers, images, networks, and volumes without touching the command line. Its curated app marketplace offers one-click installation of 165+ trusted open-source applications including Nextcloud, Bitwarden, Umami analytics, WordPress, and NocoBase, each running in isolated containers for maximum security. Native AI capabilities set 1Panel apart from every competing panel: deploy Ollama LLMs directly from the dashboard, spin up OpenClaw personal agents, monitor GPU utilization, and manage AI models through a unified interface. Website management includes automatic domain binding, Let's Encrypt SSL certificate provisioning, and Nginx configuration with zero manual setup. Security runs deep with built-in firewall rules, fail2ban integration, container isolation, WAF protection, and comprehensive audit logging enabled from day one. Automated backups support AWS S3, Cloudflare R2, and local storage with one-click restore from any snapshot. The panel supports Debian, Ubuntu, CentOS, and Rocky Linux across x86_64, aarch64, armv7l, ppc64le, and s390x architectures. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Cockpit puts Linux server administration in a web browser, rendering storage, networking, containers, and virtual machines as visual panels you click through instead of command-line syntax you memorize. It ships in every major Linux distribution and activates through systemd socket activation, consuming zero resources until someone connects on port 9090. What makes it different from other admin panels: every change through the web interface appears instantly at the command line, and every terminal change reflects in the browser in real time. No abstraction layer sits between the UI and the operating system, which means no configuration drift. Storage management covers disk partitioning, RAID arrays, LUKS encryption, LVM volumes, and NFS shares. Network configuration handles bonds, bridges, VLANs, and firewall zones through visual editors. Native Podman integration pulls images, creates containers, manages pods, and provides terminal access into running processes. KVM/libvirt support handles VM creation, cloning, snapshots, and live migration with console access. A built-in terminal provides shell access when the web interface is not enough, and the journal viewer filters systemd logs by severity and unit. Multi-server management connects additional hosts over SSH, presenting a unified dashboard across your entire infrastructure from one browser tab. Runs on a dedicated RepoCloud VPS with full root SSH access and browser serial console. LGPL licensed.

Project AIRI is the most popular open-source AI companion platform — a self-hosted recreation of Neuro-sama that brings AI-powered virtual characters into your world across web, desktop, and mobile. The system renders Live2D, Spine, and VRM 3D character models with auto-blink, eye tracking, and lip-sync driven by real-time voice synthesis, while the xsAI abstraction layer connects to 40+ LLM providers including OpenAI GPT-4, Anthropic Claude, Google Gemini, DeepSeek, and local models via Ollama and OpenRouter. Built from day one on WebGPU, WebAudio, Web Workers, WebAssembly, and WebSocket technologies, the browser version runs entirely client-side with PWA offline support while the server runtime enables persistent memory via PostgreSQL with pgvector embeddings and DuckDB WASM for client-side storage. The Minecraft agent plays autonomously using mineflayer with pathfinding, and a Factorio integration provides cooperative gameplay. Social integrations deploy your companion as a Discord bot joining voice channels, a Telegram bot, and a Twitter/X agent posting and replying autonomously. The desktop Stage Tamagotchi app provides an always-on-screen companion for Windows and macOS, while Stage Pocket brings the experience to mobile. Voice features include client-side speech recognition via VAD, multiple TTS providers including ElevenLabs, and screen vision capabilities. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Backed by 27,700+ GitHub stars and actively developed with the v0.9.x architectural overhaul introducing an event-driven plugin ecosystem, ArchiveBox delivers the open-source self-hosted web archiving platform that preserves websites, bookmarks, social posts, media, source code, and research material in durable formats before link rot, platform shutdowns, and censorship erase them permanently. Feed it URLs one at a time or schedule automated imports from browser history, RSS feeds, Pocket, Pinboard, Instapaper, Wallabag, Shaarli, JSON, CSV, HTML bookmark exports, and browser extension captures. Each snapshot stores redundant copies as original HTML, rendered single-file HTML via SingleFile, full-page PDF, screenshot PNG, WARC archive, article text via Readability, favicons, HTTP headers, media files via yt-dlp, git repository clones, and structured metadata in SQLite. The Docker Compose deployment bundles Chrome, wget, curl, yt-dlp, SingleFile, and Readability parsers with automatic dependency management and isolation. Interact through the self-hosted web UI with search, tagging, and admin controls, the comprehensive CLI for batch operations, the REST API for programmatic access, or the Python API for custom integrations. The new abx-plugins system enables community extractors with per-plugin configuration, while the append-only-log architecture provides resumable crawls and audit trails. S3, B2, and Google Cloud storage backends sync archives to remote storage via rclone. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.