Sonarr
Add a series once, set a quality profile, and everything downstream is automated: Sonarr is the smart PVR for Usenet and BitTorrent users. It monitors RSS feeds from your indexers, detects new episodes the moment they release, sends matching grabs to SABnzbd, NZBGet, qBittorrent, Deluge, or another download client, then renames files with fully configurable templates, sorts them into consistent folder structures, and notifies Plex, Kodi, or Jellyfin to update the library. Quality profiles define what's acceptable (HDTV, WEB-DL, Blu-ray, up to 4K) and an upgrade cutoff - when a better release appears, Sonarr replaces the existing file automatically, stepping from HDTV to WEB-DL to Blu-ray until the cutoff is met. Custom formats add weighted scoring for finer-grained release selection, with community-maintained TRaSH Guides presets as the widely accepted defaults. Failed downloads are handled without intervention: Sonarr retries with another release, and manual search shows every candidate with the reasons any was rejected. It scans existing libraries for missing episodes, fully supports specials, multi-episode files, and daily and anime series types, and a calendar view shows upcoming episodes across every tracked show. Runs on Linux, Windows, macOS, and Raspberry Pi, and pairs naturally with Prowlarr for centralized indexer management.
Statping-ng
A status page and uptime monitor in one Go binary: Statping-ng - the actively maintained fork of Statping - replaces the UptimeRobot-plus-Statuspage combo with a ~20 MB Docker image using under 50 MB of RAM. It checks services over HTTP, TCP, UDP, ICMP ping, and gRPC health checks on configurable intervals, with per-service timeouts, expected status codes, POST requests with custom JSON bodies, SSL verification, and failure thresholds before alerting. The public status page is the differentiator against plain monitors: visitors see live status, uptime percentages, and latency charts grouped into service categories, with incident announcements and scheduled-maintenance messages you publish from the dashboard - and Sass-based custom styling matches the page to your brand rather than a vendor template. When something fails, notifiers fire immediately: Slack, Discord, Telegram, SMTP email, PagerDuty, Twilio SMS, Pushover, and custom webhooks, each testable before saving. Because notifiers are single Go files, the plugin system makes new channels straightforward. A RESTful API manages services and reads uptime data programmatically, and the free Statping mobile app connects to your server via QR code for on-the-go monitoring. Data persists to SQLite, MySQL, or PostgreSQL. Point it at internal services too - anything the container can reach is monitorable.
Substreamer
A free, polished web client for Subsonic-compatible music servers: Substreamer is the browser-based frontend you point at your existing streaming backend to play your own library from anywhere. It speaks the Subsonic API (v1.13 and higher), which makes it compatible with the whole ecosystem that has grown around that protocol: the original Subsonic server, its forks Airsonic and Madsonic, and modern implementations like Navidrome and Ampache. That decoupling is the point - your music files, transcoding, and library indexing live on whichever server you prefer, while Substreamer provides the listening experience: browse by artist, album, and genre, build and manage playlists, search your collection, and stream on demand. This RepoCloud deployment runs the containerized web edition, so the same interface is available from any browser without installing a native app, and it pairs with the Substreamer mobile apps that made the client popular. For anyone assembling a self-hosted Spotify replacement - typically Navidrome for the backend plus a good client - Substreamer fills the client half with a clean, familiar player UI. Because it is a stateless client, the container is lightweight and low-maintenance: connect it to your server's URL and credentials, and your entire collection is streaming in minutes, with no subscription and no catalog that can disappear.
TavernAI
Character-based chat and storywriting with large language models: TavernAI is the open-source frontend that leaves model choice to you. It generates no text itself; it connects to the backend of your choice - OpenAI (including GPT-4), Anthropic Claude, KoboldAI and KoboldCpp, Oobabooga's Text Generation Web UI, NovelAI, Ollama, and the crowdsourced Horde - so cost, model quality, and content policy are decided by your backend, not the interface. Characters are defined by portable card files in PNG or JSON format with personality, scenario, and example dialogue, and tens of thousands of community-made cards from sites like Chub.ai import directly. Conversations support group chats with multiple characters, a story mode for long-form writing, message swiping to branch between alternative responses, and full editing of any message. World Info injects lore into context when keywords trigger, keeping long roleplays consistent. Themes, custom backgrounds, and configurable generation settings round out the interface. It runs on Node.js, and the SillyTavern project began as a fork of it.
The Lounge
"Forget about bouncers" became a real sentence because of The Lounge: a Node.js web IRC client that holds persistent connections to your networks 24/7, logging everything while you sleep, so closing the browser tab never means missing a message or losing your place in a channel. Open it again from any device - desktop, phone, tablet - and you resume exactly where you left off, with full history synchronized. Because it combines bouncer and client in one process, the experience feels like a modern chat app rather than 1990s infrastructure: push notifications for highlights and private messages (with self-generated VAPID keys, so even Web Push needs no third-party service), automatic link previews, inline file and image uploads, and full IRCv3 protocol support. It installs as a progressive web app from any modern browser, so phones get a native-feel client without an app store. Multi-user support means one instance serves your whole team or community, each user with their own networks and history, and LDAP integration ties into existing authentication. A public mode alternatively serves as an open, registration-free web chat for events or support channels. MIT-licensed, born as a fork of Shout, and a fixture of self-hosting stacks since.
Thumbor
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.
ToolJet
Retool's job, self-hosted: ToolJet is an open-source low-code platform for building internal tools, dashboards, and admin panels. Apps are assembled in a drag-and-drop visual builder with 60+ responsive components, including tables, charts, forms, and lists, and connected to 80+ data sources: PostgreSQL, MySQL, MongoDB, REST and GraphQL APIs, cloud storage, and common SaaS tools. When visual configuration is not enough, you can run JavaScript or Python inline for queries and transformations. A built-in no-code database (ToolJet Database) covers apps that need their own tables without provisioning an external database, Workflows add node-based automation for background jobs with dedicated worker containers and a Redis-backed queue, and multi-page apps with multiplayer editing, inline comments, and mentions support team development. Security is designed for internal data: credentials are AES-256-GCM encrypted, data flows proxy-only through your server so database contents never reach a third-party cloud, and granular per-app access control plus SSO gate each tool. Where Retool-style platforms bill per builder and sometimes per end user, the self-hosted Community Edition serves unlimited builders and users at hosting cost, and full source availability means the platform itself can be forked, audited, and extended. The stack is Node.js and React on PostgreSQL, deployed via Docker.
Twenty
Salesforce's core workflow, open-source and on your own server: Twenty is a modern CRM built as exactly that alternative. It ships the standard CRM objects out of the box: people, companies, opportunities, notes, and tasks, displayed in table and kanban views with drag-and-drop and real-time updates. Its defining technical feature is a metadata-driven data model: you define custom objects and fields in the UI, and the backend regenerates its GraphQL schema at runtime, so a new object gets working queries, mutations, filters, and sorting within seconds, with no migrations to run - adapting the CRM to your sales process never requires code changes. A REST API is auto-generated from the same schema, GraphQL subscriptions push real-time updates, and webhooks fire on record changes for external integration. A visual workflow builder automates actions like notifications and field updates, TypeScript-based apps extend the platform with custom logic and frontend components, and email and calendar sync pulls Gmail messages and meetings onto contact timelines so communication history sits next to the record. The stack is NestJS with TypeORM, PostgreSQL, Redis, and BullMQ on the backend, React with Jotai on the frontend. Self-hosting on RepoCloud means unlimited users with no per-seat licensing - the pricing model that penalizes growing teams on commercial CRMs - and your pipeline, contacts, and deal history live in your own PostgreSQL database rather than a vendor's.
Typebot
A fair-source chatbot and conversational-form builder: Typebot assembles conversations in a visual graph editor. In a visual graph editor you chain blocks from four categories: bubbles display text, images, video, audio, and embeds; inputs collect data through text fields, email, phone, buttons, picture choices, date pickers, file uploads, and Stripe payments; logic blocks handle conditional branching, variables, URL redirects, A/B testing, and custom JavaScript; integration blocks call webhooks, OpenAI, Google Sheets, Google Analytics, Meta Pixel, Zapier, Make, and Chatwoot. Build once, deploy anywhere: custom domains, WhatsApp, or embedded in any site as a container, popup, or chat bubble through a fast native JS library with no iframe and no external dependencies - plus an HTTP API for executing bots programmatically from any language. Theming covers fonts, colors, roundness, and shadows with custom CSS and reusable templates, and results arrive in real time with drop-off and completion analytics plus CSV export. Two Next.js apps (builder and viewer) self-host via Docker under the Functional Source License, which converts to Apache 2.0 after two years.
Vaultwarden
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.
Verdaccio
Private npm packages without shipping code to the public registry or paying for npm Enterprise: Verdaccio is the standard lightweight, zero-config private registry and caching proxy. It runs as a single Node.js process with its own tiny embedded database; no external database is required to start. Point npm, yarn, or pnpm at it and everything behaves as expected: install, publish, unpublish, dist-tags, and deprecation all work against the standard npm endpoints. The uplink system is where it earns its keep: packages not found locally are fetched from configured upstreams (npmjs.org, yarn, JFrog, Nexus, or another Verdaccio), cached as tarballs, and served locally thereafter - cutting CI latency and surviving registry outages. Multiple uplinks chain for failover, and per-package glob patterns in config.yaml route scopes to specific upstreams while controlling access, publish, and unpublish rights per group. You can even override a public package by publishing a patched version under the same name locally. A plugin architecture swaps in auth backends (htpasswd default, LDAP and others available), storage drivers (S3, Google Cloud Storage), middleware routes, and metadata filters. With official Docker images and a Kubernetes Helm chart, it slots into any pipeline in minutes.
Weblate
Over 2,500 open-source projects and companies in more than 165 countries localize with Weblate - the libre continuous localization platform and the standard self-hosted answer to Crowdin and Lokalise. Its defining trait is that translations live in the same version control as your code: Weblate talks directly to Git and Mercurial, pulls new source strings automatically via webhooks, and pushes finished translations back either as direct commits or as pull/merge requests on GitHub, GitLab, Gitea, Bitbucket, Azure DevOps, Gerrit, or Pagure. Every translator is properly credited in the commit history. For translators, it is a full computer-aided translation tool: translation memory, glossaries, customizable quality checks that catch placeholder and formatting mistakes, propagation of identical strings across components, and automatic suggestions from machine translation services - DeepL, Amazon Translate, LibreTranslate, and others, with per-service priorities and support for custom Python engines. It handles the format zoo (gettext PO, JSON, YAML, Android XML, iOS strings, and dozens more) and supports crowdsourced workflows with granular access control, workspaces, two-factor authentication, and reviewer approval steps. A REST API, CLI client, and add-on system automate everything else. Built on Python/Django, GPL-licensed, with no per-string or per-seat pricing when self-hosted.
Wizarr
Getting non-technical friends and family onto a media server is its most tedious chore - Wizarr solves it. Instead of manually creating accounts, dictating server addresses, and explaining which app to install, you send one invite link. When the recipient clicks it, Wizarr creates their account on your server automatically - Plex, Jellyfin, Emby, Audiobookshelf, Komga, Kavita, and Romm are all supported - then walks them through a mobile-first, app-like onboarding wizard: download the right client, sign in, and learn how to request movies through your Overseerr or Ombi instance, with an optional Discord server invite along the way. Invitations are genuinely manageable: set expiration dates, usage limits, passphrases, library-scoped access tiers, and time-limited memberships that end access automatically. The wizard itself is fully customizable - Markdown-based steps managed from the admin UI, organized into pre-invite and post-invite phases (terms of service before joining, app setup after), reorderable bundles assignable to specific invitation types, and combined flows for invites spanning multiple servers. Multi-server and multi-admin support manages several backends from one dashboard, SSO support is plug-and-play, and a REST API with OpenAPI/Swagger documentation covers automation. A Flask/HTMX app in a single Docker container.
YOURLS
Ever wanted to shorten your URLs without feeling like you just handed over your life savings to a corporate giant? Enter YOURLS, the self-hosted URL shortener that lets you take control of your links like a boss! With a sleek interface that’s easier to navigate than your grandma’s Facebook page, you can create and manage short URLs while keeping your branding intact. Plus, it’s got plugins galore—because who doesn’t love a little extra functionality? And let’s not forget the detailed analytics that’ll make you feel like a data scientist, tracking clicks like a hawk on a mission. Accessible on ports 8080 and 8081, YOURLS is like the Swiss Army knife of URL shortening, but without the risk of cutting yourself. So why let the big guys take your links hostage when you can self-host your own? Deploy YOURLS today and give your URLs the makeover they deserve, all while saving enough cash to treat yourself to that fancy coffee you’ve been eyeing!
Whoogle
Google's search results without Google's surveillance: Whoogle is a self-hosted proxy that strips the tracking and keeps the results. Your query goes from browser to your Whoogle instance, which fetches results from Google with a randomly generated User Agent and strips everything hostile before returning them: no ads or sponsored content, no third-party JavaScript or cookies, no AMP links, no URL tracking tags like utm_source, no referrer header - and Google sees your server's IP, never yours. Unlike metasearch engines that blend sources, Whoogle proxies Google exclusively, so result quality is exactly what you'd get logged out and incognito, minus the noise. A lightweight Flask app configured entirely through environment variables, it supports DuckDuckGo-style bang shortcuts, autocomplete suggestions, safe search, per-country and per-language filtering, site blocklists, and automatic rewriting of social links to privacy front-ends like Nitter and Invidious. Privacy hardening goes further: built-in Tor routing makes Google see an exit node instead of your server, HTTP/SOCKS proxy support covers other setups, and POST-based queries keep search terms out of logs. Light, dark, and fully custom CSS themes plus browser search-engine registration make it a drop-in default on desktop and mobile. Stateless, tiny, and trivial to run.
WBO
A Node.js server, a large shared canvas, and a URL - WBO (Whiteboard Ophir) is collaborative whiteboarding reduced to its essence. There are no accounts and no setup - to collaborate, you send someone the board's link, and every stroke appears for all connected users in real time over WebSockets, with cursor positions shared so you can see where collaborators are working. Board state persists automatically and continuously, so a diagram drawn in today's lesson is still there next week at the same URL. Boards come in three flavors: a public free-for-all, private boards with random unguessable names, and named boards with custom URLs shared by anyone who knows the name. The tools cover teaching and brainstorming needs - pencil, straight lines, rectangles, ellipses, text annotations, eraser, a full color palette with brush sizes - and boards export as SVG or PNG. Despite the simplicity, the server is production-minded: JWT authentication gates board access with granular capabilities (open, edit, and clear as separate permissions), rate limiting caps per-client message volume, reverse-proxy and subpath deployment are supported, and OpenTelemetry provides metrics, logs, and traces. It works on tablets and touch devices, speaks multiple languages, and consumes minimal resources. AGPL-licensed.
Restreamer
Point OBS or a hardware encoder at Restreamer's built-in RTMP or SRT ingest and it serves your website while rebroadcasting to YouTube Live, Twitch, Facebook, Vimeo, TikTok, LinkedIn, PeerTube, and anything else that accepts RTMP, SRT, or HLS - a complete self-hosted live-streaming server from datarhei. That multistreaming normally costs a monthly Restream.io subscription; here it's one FFmpeg process per destination on your own hardware. The web UI is genuinely approachable, with a wizard that walks beginners through camera setup, while professionals get the full surface: multiple audio/video inputs (USB, RTSP network cameras, virtual devices), codec and processing settings, separate audio muxing, and hardware acceleration via Nvidia CUDA, Intel VAAPI, or Raspberry Pi. Serving your own audience is first-class - a built-in Video.js player embeds in your site, a ready-made publication website streams without any embedding work, HLS chunk sizes are tunable, and automatic Let's Encrypt handles HTTPS. Viewer and bandwidth monitoring with limits keeps traffic costs predictable, and it's GDPR-friendly: no third-party provider, no audience data stored. A fully Swagger-documented REST API drives automation. SRT support keeps latency under a second.
Calcom
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.