Open Source App Cloud Marketplace

Matrix's flagship client, built by the protocol's creators: Element brings the decentralized open standard for real-time communication to web, desktop, iOS, and Android. Paired with a Matrix homeserver, it delivers Slack-quality team messaging where you own every message, file, encryption key, and byte of metadata. End-to-end encryption is on by default, built on Olm and Megolm - the Double Ratchet algorithm family Signal popularized, extended for large-room scalability and publicly audited by NCC Group. Messages encrypt per-device with cross-signed device verification, so even a compromised server yields nothing readable. Federation is the defining capability: like email, users on different homeservers converse seamlessly, and 30+ bridges connect Matrix rooms to Slack, Discord, WhatsApp, and Telegram, so moving to sovereign infrastructure doesn't sever contact with anyone. Rooms support threads, reactions, file sharing, and voice and video calls via Element Call. The result is digital sovereignty chosen by governments and enterprises across Europe: your data sits on your server in your jurisdiction, portable to any other Matrix host because the protocol is an open standard. Apache-2.0 licensed, with no per-user fees at any scale.

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.

Grammar, punctuation, and style errors a dictionary lookup can't see: LanguageTool is open-source proofreading powered by a Java rule engine covering English, German, Spanish, French, Portuguese, Dutch, and 25+ other languages. Self-hosting the HTTP server is how you get Grammarly-class checking without sending every sentence you write to a third party - a real concern when the text being proofread is confidential email, legal drafts, or unreleased documentation. Your instance exposes the standard /v2/check API, so the official ecosystem plugs straight in: browser extensions for Chrome and Firefox accept a custom server URL, and integrations exist for VS Code, LibreOffice, Obsidian, Vim, Emacs, and many editors. Notably, self-hosting restores free browser-extension checking that the hosted service moved behind a premium subscription - your server, no character limits, no paywall. Detection quality is tunable: optional n-gram datasets (multi-gigabyte language models for en, de, es, fr, nl) teach the engine word-order and confusion-pair errors like there/their and brakes/breaks, and a fastText model improves automatic language identification. Everything runs offline once models are downloaded. The core is LGPL, the API is documented with Swagger, and rules are community- maintained and constantly expanding.

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.

"Less is more" is Kanboard's stated philosophy, and the free, MIT-licensed PHP application lives it: drag tasks between customizable columns, enforce work-in-progress limits per column, and slice boards horizontally with swimlanes for releases, teams, or priorities. Tasks carry what matters - colors, categories, subtasks with time estimates, Markdown descriptions, comments, attachments, internal links, and due dates - and move or duplicate across projects in one click. A concise query language filters any board dynamically (assignee, category, due date, description), and saved filters become custom views. The automatic-actions engine kills repetitive triage: on events like column moves or task creation, Kanboard reassigns, recolors, recategorizes, or closes tasks by rule. Around the board sit a calendar, per-project analytics (cumulative flow, lead and cycle time), Gantt view, and time tracking. Authentication spans LDAP/Active Directory, Google, GitHub, GitLab, and reverse-proxy headers; a JSON-RPC API, webhooks for creating tasks from external systems, and a CLI cover integration. A large community plugin catalog adds what core deliberately omits. With no external dependencies, it runs happily on anything from a Raspberry Pi up - translated into 30+ languages.

Hold Alt/Option, click any string in your running app, and edit the translation in place: Tolgee is an open-source localization platform built the way developers wish translation worked - changes save straight to the platform with no hunting through JSON or PO files. In-context editing works even in production via the Tolgee Tools browser extension, which injects credentials without touching source code, so a client or colleague with zero coding skills can translate the product inside the product. The SDKs (React, Angular, Vue, Svelte, plus iOS and Android) extract context from each UI element and capture one-click screenshots, giving both human translators and machines the surrounding meaning that raw string files lose. Autonomous translation uses that context: new keys are instantly filled from translation memory or machine translation (DeepL, Google Translate, AWS Translate), with optional human review afterward - shipping no longer waits on a translation agency. A CLI handles import/export, a REST API covers automation, a Figma plugin bridges design, and an MCP server lets AI coding assistants search keys, create translations, and trigger machine translation without leaving the editor. Self-hosting this Crowdin/Phrase/Lokalise alternative keeps every string, screenshot, and API key on your infrastructure.

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.

Deployment decoupled from release: Unleash, the most popular open-source feature management platform on GitHub, is a Node.js server backed by PostgreSQL. Ship code dark, then control who sees it through activation strategies: gradual percentage rollouts, targeting by user ID, IP, hostname, or application name, custom constraints against your own context fields, and scheduled or time-limited releases. Strategies stack - a flag activates if any strategy matches - and strategy variants layer A/B versions on top of the on/off decision. Each flag carries per-environment configurations, so a feature can run at 100% in staging while canarying at 5% in production. Backend SDKs (Node.js, Java, Go, Python, Ruby, .NET, PHP, Rust, and more) fetch configuration and evaluate flags locally, so a flag check adds zero network latency to request paths; frontend SDKs for React, Vue, Svelte, iOS, Android, and Flutter evaluate through a proxy layer. Flag hygiene is built in: flags are typed (release, experiment, operational, kill-switch, permission) with expected lifetimes, and Unleash marks overdue flags as potentially stale and surfaces unknown flags your SDKs request but that don't exist. Self-hosting via Docker keeps flag data, targeting rules, and evaluation infrastructure entirely on your side.

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.

The antidote to doomscrolling: Upvote RSS turns Reddit, Hacker News, Lemmy, Lobsters, PieFed, Mbin, and trending GitHub repositories into calm, filtered RSS feeds. The MIT-licensed PHP app's killer feature is intelligent filtering: beyond simple score thresholds, the "posts per day" filter analyzes a community's recent history and computes the score cutoff that yields your target volume - say, exactly three r/technology posts daily - while a percentage-based threshold mode stays consistent as communities grow. Feeds are rich, not bare links: parsed full-article content via Readability (with optional Readability.js, Mercury, or Browserless for JavaScript-heavy pages), embedded videos and image galleries, top-voted comments with pinned-moderator filtering, scores, reading-time estimates, and optional AI summaries through Ollama, OpenAI, Gemini, Anthropic, Mistral, DeepSeek, or any OpenAI-compatible endpoint - with automatic provider fallback. A web UI builds the feed URL interactively with live preview; paste the result into any RSS reader. Reddit support includes custom domains like old.reddit.com plus NSFW filtering and blurring. Caching via filesystem, Redis, or APCu keeps repeated fetches cheap and avoids re-running paid summarizations.

Send a document, receive a PDF: Gotenberg is a Docker-based, stateless HTTP conversion API trusted in production by thousands of companies and adopted by notable open-source projects. Send files as multipart/form-data, get a PDF back; Chromium, LibreOffice, and fonts are the container's problem, not yours. Headless Chromium handles URLs, HTML templates, and Markdown with pixel-perfect browser rendering: it executes JavaScript, loads web fonts, waits for network idle, a JS expression, or a DOM selector before rendering SPAs, and accepts injected cookies and HTTP headers for authenticated pages. LibreOffice converts 100+ office formats - .docx, .xlsx, .pptx, and legacy formats - with page-range extraction and PDF/A archival conformance. Built-in PDF engines round out the pipeline in every image variant: merge, split, rotate, flatten, encrypt, watermark, stamp, read/write metadata and bookmarks, plus Factur-X/ZUGFeRD e-invoicing and PDF/UA accessibility compliance. Screenshots of URLs and HTML come from the same endpoints. Zero-transfer pipelines stream files directly between S3, MinIO, or GCS presigned URLs and Gotenberg, bypassing your application entirely, and webhooks enable async processing. Statelessness means horizontal scaling is trivial - run as many replicas as your conversion volume demands. Three image variants (full, Chromium-only, LibreOffice-only) trim the footprint to what you actually use.

Unlimited agents, unlimited tickets, unlimited mailboxes, forever, on a $4 VPS - FreeScout's pricing inversion is why it became the most popular self-hosted Help Scout alternative, a PHP/Laravel help desk and shared inbox developed from scratch over eight years. The inbox deliberately behaves like Gmail or Outlook, so new support agents need close to zero training. The email-support core is genuinely complete: seamless IMAP/SMTP integration including modern Microsoft Exchange authentication, collision detection that warns when two agents open the same conversation, canned responses, auto-replies, internal notes, open tracking, starring, forwarding, merging, and moving conversations between mailboxes, phone-call logging, push notifications, and an auto-refreshing conversation list - plus screenshot pasting straight from the clipboard into replies. It's 100% mobile-friendly, fully screen-reader accessible, and translated into 28 languages. Beyond the core, an ecosystem of 100+ modules (mostly one-time $12-20 purchases) adds knowledge base, workflows with Gmail-filter-style automation rules, satisfaction ratings, time tracking, tags, custom fields, LDAP, Slack, WhatsApp and Telegram channels, and an API with webhooks - pay only for what your team needs. Web installer and updater included. AGPL-licensed.

Plex's own dashboard shows current streams and forgets everything else - which is why every Plex server admin eventually installs Tautulli, the analytics layer. This Python web application (descended from PlexWatch and Headphones) logs complete watch history - what was watched, who watched it, when, where, from which device and IP, and whether it played directly or transcoded - and turns it into clean Highcharts graphs of daily plays, concurrent streams, bandwidth, and platform breakdowns. The home page surfaces top statistics over configurable windows: most-watched content, most active users, stream type ratios. For running a server shared with family and friends, this is operational truth: spot the user forcing 4K transcodes on a phone, see which libraries earn their disk space, and track sync activity across users. The notification engine triggers on server events - playback starts, transcode decision changes, recently added media, server down - through dozens of agents (Discord, Telegram, Slack, email, webhooks) with fully customizable text and conditions, plus arbitrary script execution. Scheduled newsletters email your users a styled digest of recently added content. A comprehensive API exposes every statistic for dashboards like Homarr, and an official mobile app monitors activity on the go. Themed to match Plex/Web. GPL-licensed.

A deliberately simple ticketing system standing in for both Zendesk and Jira: Peppermint handles internal staff requests and external customer support alike. The stack is modern full-stack TypeScript: Next.js and React over Prisma and PostgreSQL, which makes it light to run and approachable for developers extending it. Ticket creation is straightforward - a markdown editor with file uploads, assignment, status tracking, and a logical workflow that new agents grasp without a manual. Mailbox integration converts email into tickets automatically: configure SMTP/IMAP per mailbox and incoming messages become trackable tickets. Each client accumulates an interaction history, giving agents context on every past request before replying. Two touches distinguish it from bare-bones ticketing: a built-in markdown notebook with todo lists for internal documentation and knowledge sharing, and OIDC authentication so agents sign in through your existing identity provider - Keycloak, Okta, Authentik, or Azure AD. Configurable webhooks and email notifications push ticket events to third-party services. The UI is responsive from mobile to 4K, and everything works fully offline in air-gapped environments. Docker-native and scalable via Kubernetes, with an active community of 3,000+ GitHub stargazers.

Its author, a student and WakaTime fan, didn't want to pay $9/month for data about his own keystrokes - so Wakapi was born, a self-hosted, WakaTime-compatible backend for coding statistics. The compatibility is the killer design decision: the official WakaTime plugins for VS Code, JetBrains IDEs, Vim, and dozens of other editors work unmodified - just point the plugin's API URL at your Wakapi instance with your personal key, and heartbeats flow to your server instead of a third party's. Duration inference matches WakaTime's own algorithm, with a configurable timeout (10 minutes by default). From that stream Wakapi builds statistics and plots across projects, languages, editors, hosts, and operating systems, plus the fun extras: public leaderboards (optionally login-gated, with configurable aggregation windows), badges for GitHub readmes, and weekly email reports. A REST API serves your data programmatically, Prometheus export feeds your existing Grafana, and a WakaTime relay mode can mirror heartbeats to both services during migration - with one-click import of historical WakaTime data. Written in Go, it is lightning fast and light enough for the smallest instance, storing to SQLite, PostgreSQL, or MySQL, with configurable data retention for GDPR peace of mind. Deliberately smaller than WakaTime, deliberately yours.

Vehicle maintenance records shouldn't live in a homemade spreadsheet and a shoebox of receipts - LubeLogger exists because of exactly that. It's a self-hosted .NET web application (from Hargata Softworks) that gives every vehicle in your garage a complete digital history: service, repair, and upgrade records categorized and searchable, with invoices and receipts attached as documents; fuel fill-ups that compute economy in MPG, UK MPG, L/100KM, or KM/L without spreadsheet tedium; taxes, odometer logs, inspections, equipment, and supplies inventory for tracking the parts and fluids on your shelf. The reminder system is what saves engines: recurring reminders trigger by date, odometer reading, or whichever comes first - exactly how real service intervals work - so oil changes and timing belts stop relying on memory. A dashboard summarizes expenses by year, month, and category, a planner tracks to-dos by type, priority, and progress, and professional vehicle reports print a full history - genuinely useful when selling a car. Collaboration is built in: invite household members as collaborators on shared vehicles, with single sign-on support. Custom fields adapt records to your needs, CSV import/export moves data freely, an API enables automation, and the mobile-tested UI installs as a PWA on iOS and Android. MIT-licensed.

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.

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.