Open Source App Cloud Marketplace

A web interface for a folder of Markdown files - Flatnotes is exactly that, and the discipline of that design is why people love it. Every note is a plain .md file in a single flat directory: no database, no proprietary format, no hierarchy to maintain, no export step if you ever leave. Edit notes in the browser or open the same files in VS Code or Obsidian, sync them with Syncthing or rsync while the app is running - the Whoosh-powered search index synchronizes incrementally, so external edits just show up. The interface is a clean Vue.js app with both WYSIWYG and raw Markdown editing modes (TOAST UI Editor), instant full-text search behind the "/" shortcut with partial-match support, wikilinks for cross-note references, and automatic tag extraction from #hashtags in note bodies. Light and dark themes and a mobile-responsive layout make it pleasant everywhere. Authentication is flexible for a personal tool: none, read-only, username/password, or TOTP two-factor. A documented REST API covers create/read/update/delete for automation. The operational story is the quiet selling point - the only state is the notes folder and a rebuildable index, so backup is copying a directory. For a personal notepad that respects your data, Flatnotes nails minimal.

The fediverse's answer to YouTube comes from French non-profit Framasoft: PeerTube is a TypeScript/Angular video platform where hundreds of independently operated instances federate over ActivityPub into one network. Videos you publish are discoverable across the whole video fediverse, and viewers can follow your channels from Mastodon or any ActivityPub platform - or plain RSS - without needing an account on your instance. The namesake innovation attacks video hosting's core cost problem: alongside HLS delivery, an optional WebRTC-based P2P layer lets concurrent viewers' browsers share video segments with each other, so a video going viral distributes its own bandwidth demand instead of crushing your server; instance redundancy extends this by letting friendly instances cache each other's videos. Livestreaming is first-class - stream via OBS or any RTMP software, host permanent streams, enable replays, and interact through live chat. Creators get channels, playlists, analytics, built-in video editing (trim, watermark), and an embeddable player for any website. There are no ads, no data mining, and no recommendation algorithm engineered for watch-time - the project's explicit design stance. Admins control federation policy, P2P settings, and theming; a plugin system extends the rest. AGPL-licensed, 300+ contributors, in active development since 2015.

The project that proved organizations could have Dropbox-style convenience with complete data ownership: ownCloud is the original open-source file sync and share platform - the codebase Nextcloud later forked from. This deployment runs the classic ownCloud Server (PHP over PostgreSQL or MariaDB, with Redis caching), the battle-tested edition trusted across enterprises, universities, and public institutions worldwide. The core loop: store files on your server, sync them via desktop clients for Windows, macOS, and Linux plus iOS and Android apps, and access everything through the web interface or standard WebDAV. Sharing is granular - internal users and groups, external recipients via public links with passwords and expiration dates, and federated sharing that connects separate ownCloud instances into one network. Security controls include file firewall rules, multi-factor authentication, encryption, and detailed audit-friendly lifecycle management with versioning and trash-bin recovery. An app marketplace extends the platform, and Web Office integrations bring collaborative document editing through Collabora Online, OnlyOffice, or Microsoft Office Online directly into your files. LDAP and Active Directory integration slots it into existing identity infrastructure. For teams that need a proven, self-hosted alternative to Dropbox or Google Drive - where compliance demands knowing exactly which disk your data sits on - ownCloud remains a foundational choice.

For people whose notes number in the tens of thousands, Trilium Notes is the hierarchical note-taking application built specifically for large personal knowledge bases - actively maintained as TriliumNext. Notes arrange into arbitrarily deep trees where every note is both content and container, and cloning lets a single note live in multiple places at once - bash notes belong under both Linux and Scripting, and Trilium refuses to make you choose. A WYSIWYG editor handles rich text, tables, math, and syntax-highlighted code blocks with Markdown-style shortcuts, while dedicated note types cover Excalidraw sketches, mind maps, geo maps with GPX tracks, relation maps that visualize connections between notes, and tables with typed columns. The attribute system is the power layer: labels attach queryable metadata (#year=1999, #author), relations create named links between notes, and both inherit down the tree - feeding full-text search, saved queries, and scripting. Scripting is Trilium's deepest differentiator: JavaScript code notes run on events like note changes or hourly schedules, build custom widgets, and add server-side logic, turning the knowledge base into a programmable platform. Protected notes encrypt sensitive content, note hoisting focuses on subtrees, and the self-hosted server syncs desktop clients across devices.

Most design tools stop at prototyping; Quant-UX also measures how real users actually perform with the prototype. The visual editor creates prototypes that behave like real apps - functional input widgets, animations, form validation, data binding across screens, and business logic modeled with REST requests and decision elements. Design systems are first-class, with components, design tokens, and master screens; if you design elsewhere, drop in image files or import from Figma. Testing is a shared link or QR code - no installs on the tester's side. Define user tasks up front, and Quant-UX records every session: click heatmaps show where users found (or missed) actionable elements, user journey graphs expose lost users, drop-off charts reveal where tasks stall, and success rates and task KPIs are extracted automatically into a dashboard. An A/B test operator wires two design variants into one prototype and compares task duration, success rate, and interaction counts. In-prototype surveys collect qualitative feedback alongside the numbers, and an AI assistant generates prototype fragments like styled forms on request. The RepoCloud deployment runs the full stack - frontend, backend, and WebSocket server containers over MongoDB - so all test recordings and research data stay on your infrastructure.

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.

A polished public status page without Statuspage prices or a heavyweight observability suite: Kener is a status and uptime monitoring system built with SvelteKit and Node.js. It runs 11 monitor types - API, Ping, TCP, DNS, SSL certificate, SQL query, Heartbeat, gRPC, and GameDig game-server checks among them - each with configurable intervals and thresholds. Incident management covers the full lifecycle: structured timelines from investigation through resolution, acknowledgements, and subscriber-visible updates, plus maintenance windows with RRULE-based recurring schedules and automatic status transitions. Notifications reach email, Slack, Discord, and custom webhooks through trigger-based workflows with template-driven messaging. One instance can serve multiple branded status pages - per product, team, or region - with custom logos, colors, and CSS, localization into 21 languages, timezone-aware displays, and server-rendered pages that stay fast and SEO-friendly. Operations tooling includes role-based access for teams, API key management, a secrets vault, analytics integrations (Google Analytics, Plausible, Umami, and others), and a REST API with 17+ endpoints for automating incidents and monitors from CI/CD. MIT-licensed; Docker deployment with Redis, SQLite by default, PostgreSQL or MySQL for production.

Mixpanel, OneSignal, and Crashlytics in one self-hosted stack - Countly is an all-in-one product analytics and engagement platform where every byte of first-party data stays on your server. A Node.js application over MongoDB, it collects through ten battle-tested SDKs spanning iOS, Android, web JavaScript, React Native, Flutter, Unity, and desktop (plus a data write API for anything else), and has powered tens of thousands of mobile, web, and desktop apps since 2012. The analytics core covers sessions, custom events, views, user profiles, and real-time dashboards, with exploration tools built for product managers as much as analysts. What separates Countly from pure analytics tools is acting on the data without third parties: built-in push notifications send automated, transactional, and personalized messages to iOS (APNs), Android (Firebase), and Huawei devices, with the SDK handling token retrieval and permission flows automatically; crash reporting captures symbolicated native crashes on iOS and Android plus JavaScript errors, correlated with the same user and session data. Email reports keep stakeholders updated, and the plugin-based architecture means features load as modules. For GDPR-sensitive products, engagement without piping user data to advertising companies is the entire point. AGPL-licensed server, installable in minutes.

A PostgreSQL database becomes a production-grade GraphQL API the moment Hasura GraphQL Engine points at it: track tables and relationships - existing schemas included - and full query, mutation, and subscription types appear with where, order_by, limit, offset, and on_conflict arguments, no resolvers or boilerplate written. Its Haskell core compiles GraphQL to efficient SQL, and any query becomes a real-time live query with a single keyword, powering dashboards and collaborative UIs over standard GraphQL subscriptions. Authorization is where Hasura earns its enterprise reputation: role-based access control with row- and column-level permission policies driven by session variables from JWTs, auth webhooks, or headers - each role effectively sees its own GraphQL schema containing only what it may touch, integrating cleanly with Auth0, Firebase, or homegrown auth. Event triggers fire webhooks on inserts, updates, and deletes for asynchronous business logic; Actions extend the schema with custom REST handlers; remote schema stitching merges external GraphQL services into one endpoint; and auto-generated REST endpoints serve clients that skip GraphQL. A browser console handles data modeling and API exploration, the CLI manages migrations and metadata as code, and deployment is a single stateless Docker container beside Postgres.

The ad-riddled "free online tools" sites people paste sensitive text into and upload confidential PDFs to - OmniTools replaces that whole ecosystem with one self-hosted app. It bundles 50+ utilities behind one clean React/TypeScript interface: image tools (resize, convert, crop, edit), video and audio tools (trim, reverse, convert), PDF tools (split, merge, edit), text and list utilities (case converters, formatters, shufflers), plus date/time, math, and data-format helpers for JSON, CSV, and XML. The architectural decision that makes it trustworthy is that all file processing happens entirely client-side in the browser - the server only serves static assets, and nothing you process ever leaves your device. That design has a pleasant side effect: the host needs almost no resources (people run it on a Raspberry Pi Zero), because your browser does the work while the server just delivers files. The Docker image is a remarkable 28 MB, making it one of the fastest apps to deploy and cheapest to keep running. There are no ads, no tracking, no accounts, and no upload limits. With multi-language support and an MIT license, it works equally well as a personal toolbox or a team-wide internal utility portal - one URL that replaces a bookmark folder full of questionable converters. Actively developed with 50 contributors and 9,500+ GitHub stars.

Configure each indexer once, not five times: Prowlarr is the indexer hub of the *arr stack, removing the most tedious duplication in a media automation setup. Instead of configuring the same torrent trackers and Usenet indexers separately in Sonarr, Radarr, Lidarr, Readarr, and Mylar3, you add each one once in Prowlarr and it syncs them to every connected app automatically, complete with category mappings; with Full Sync enabled, adding or removing an indexer propagates everywhere, and a tracker URL change is a one-place fix. Coverage is the deepest available: 500+ torrent trackers with definitions added constantly, 24 native Usenet indexers, generic Newznab and Torznab support for anything else, and custom Cardigann YML definitions with JSON and XML parsing for obscure sources. Built on the same .NET/React base as its siblings, it also earns a place as a search tool in its own right: unified manual search queries every indexer simultaneously at a category level, and you can push multiple releases straight to your download clients without touching Sonarr or Radarr. Health checks and status notifications flag failing indexers, per-indexer statistics track success rates and response times so you can cull unreliable sources, and per-indexer proxy support (SOCKS4/5, HTTP, FlareSolverr) handles trackers behind Cloudflare.

"Throw it on a haste and send the link" entered developer vocabulary because of Hastebin (haste-server), the minimalist open-source pastebin. Written in Node.js with three stated design goals - be really pretty, be really simple, be easy to set up - it does one job precisely: paste code, logs, stack traces, or config snippets, press save (or Ctrl+N for a new one), and get a short random-key URL to share. Syntax highlighting renders pastes readably across common languages, a raw view serves plain text for curl and scripts, and duplicate-and-edit makes iterating on a shared snippet trivial. The killer workflow is the terminal: with the haste-client utility or a one-line shell function, `cat error.log | haste` prints a shareable URL straight from stdout - the fastest route from a broken build to a colleague's eyeballs. Storage is pluggable through a simple adapter interface: filesystem by default, Redis with optional key expiration for pastes that should age out, and configurable key length, maximum paste size, and static documents. Self-hosting matters here because pastes often contain internal logs and stack traces that should never sit on a public pastebin - your instance keeps them inside your network, under your retention rules.

Full double-entry accounting on your own server: Manager.io Server Edition runs the same engine as the free desktop edition as a web server, so unlimited users work in unlimited businesses concurrently, with all books on infrastructure you control. The module coverage is genuinely comprehensive - general ledger with a customizable chart of accounts, sales and purchase invoices, quotes and orders, bank and cash account reconciliation, inventory with stock tracking, fixed assets with depreciation, payroll, multi-currency with exchange gains and losses, tax codes for VAT and GST regimes, and the complete reporting stack: balance sheet, profit and loss, trial balance, aged receivables and payables, and cash flow statements. The interface is translated into more than seventy languages, reflecting a genuinely global user base. The licensing model is the refreshing part: a server license is a one-time perpetual purchase, not a subscription - twelve months of updates included, optional renewals after, no per-user tiers, no data limits, and you can downgrade to the free desktop edition anytime, so your books are never hostage. Businesses wanting collaborative accounting behind their own firewall, with data sovereignty and no monthly fees, get exactly that.

Mastodon serves single-user and small-community instances poorly; GoToSocial, an ActivityPub server written in Go, was built precisely for them. Where Mastodon demands Ruby, PostgreSQL, Redis, and Sidekiq, GoToSocial is one binary using roughly 250-350 MiB of RAM with SQLite as the default database (PostgreSQL optional) - it runs comfortably on a $5 VPS or a repurposed laptop. The deliberate design choice is having no built-in web client: the server exposes profile pages, a settings panel, and a faithful implementation of the Mastodon API, and you post through the client app you already like - Tusky on Android, Feditext on iOS, Pinafore or Phanpy in the browser. Federation is the point: your instance follows, boosts, and replies across Mastodon, Misskey, Pixelfed, and the rest of the Fediverse, with your identity anchored to your own domain. Safety is a stated focus, with granular per-post visibility and interaction controls, content warnings, custom emoji, hashtag following, domain allow/blocklists, and OIDC login support. Built-in Let's Encrypt provisioning simplifies the mandatory TLS. AGPL-3.0 licensed and in active beta, federating cleanly with the ecosystem's major servers.

A single pane of glass for every service you run, arranged by drag-and-drop with no YAML or JSON files: Homarr is the modern dashboard for self-hosted infrastructure. Its grid system arranges apps, widgets, and bookmarks on desktop or touch, backed by an icon picker with over 11,000 icons. What separates Homarr from static launchers is 50+ live integrations: Plex, Jellyfin, and Emby media stats, the *arr suite (Sonarr, Radarr) with a unified release calendar, download clients, Pi-hole and AdGuard Home controls, Proxmox, Home Assistant, OPNsense, and Unifi monitoring. Widgets update in real time over WebSockets (tRPC and Redis under the hood), and a built-in search queries thousands of data points across connected services. Custom widgets extend the reach to any HTTP API without code: define endpoint, auth, and refresh interval in the management UI, then render responses as stat grids, tables, progress bars, status indicators, action buttons, or full custom JSX layouts - with an AI-prompt helper for generating templates. Multi-user support is first-class: credentials, OIDC, or LDAP sign-on, groups with granular permissions, and secrets encrypted with AES-256-CBC. A robust background-job system scales it from a Raspberry Pi homelab to deployments serving hundreds of users.

A server full of scattered services becomes one clean application hub under Flame - a self-hosted startpage where every bit of configuration happens in built-in GUI editors, never a config file. Applications and bookmarks are created, edited, and organized into categories directly in the browser, and favorites pin to the homescreen for one-click access. The integrated search bar filters your apps and bookmarks locally as you type, and prefix shortcuts (like /g for Google) route queries to any of 11 web search providers or custom ones you define, making Flame a genuine browser homepage rather than a static link wall. Docker integration is the standout for homelabs: mount the Docker socket, add flame.type, flame.name, and flame.url labels to containers, and new services appear on the dashboard automatically - Kubernetes Ingress annotations work the same way. A weather widget shows temperature, cloud coverage, and animated conditions for your coordinates, and password authentication protects settings and items. Appearance is deeply customizable with 15 built-in color themes, a custom theme builder, and full custom CSS support. The stack is Node.js with SQLite behind a React frontend - light, fast, and inspired by the minimalist SUI design.

What Jellyfin is for video, Komga is for comics, manga, BDs, magazines, and eBooks: point it at folders of CBZ, CBR, CBT, PDF, and EPUB files and it becomes a proper library with cover art, embedded metadata import, and per-user reading progress. The responsive web reader handles multiple reading modes - left-to-right for western comics, right-to-left for manga, webtoon scrolling - while collections and read lists organize crossovers and story arcs, with ComicRack .cbl read list import for existing curation. Its openness is the real differentiator: OPDS v1.2 and v2.0 feeds serve virtually every reader app (Panels, Moon+ Reader, Mihon/Tachiyomi, KyBook), with OpenSearch and page-streaming extensions so mobile apps fetch pages on demand instead of whole archives. E-ink support is built in, not bolted on - Kobo devices sync directly against Komga instead of Kobo's servers, with two-way read progress, on-the-fly KEPUB conversion via Kepubify, and optional proxying so official Kobo purchases still work; KOReader sync covers everything else. Multi-user management brings per-library access control, age restrictions, and label restrictions for family setups. Housekeeping tools detect duplicate files and duplicate pages, and a REST API feeds a healthy ecosystem of community scripts. Runs from a single Docker container with embedded SQLite.

Wire nodes together in a browser, deploy in one click, and real-time data flows from sources through transformations to outputs: Node-RED is the OpenJS Foundation's flow-based programming tool for event-driven applications. Born at IBM as a proof-of-concept for manipulating MQTT topic mappings, it has become the lingua franca of IoT and automation glue - home automation, industrial control, edge data collection - with a community library of over 5,000 contributed nodes and flows covering protocols, devices, and services. Where visual wiring runs out, JavaScript function nodes written in a rich in-editor code editor take over, and every flow serializes to importable, exportable JSON that shares cleanly and version-controls sensibly. Version 5.0 (2026) delivered the largest editor overhaul in the project's history: a rethought layout with Explorer and Information panels in a split sidebar, a native dark theme with theme variants, improved accessibility, and refreshed node appearance. The runtime is lightweight Node.js, exploiting the event-driven non-blocking model so the same flows run on a Raspberry Pi at the network edge or a cloud VM. Apache-2.0 licensed with 240+ contributors, it pairs naturally with dashboard nodes for live charts and controls.