FOSS not only plays a crucial role in enhancing learning and fostering innovation, while also promoting collaboration and building a strong community among both developers and users, it is also pivotal in delivering practical, user-friendly, and reliable solutions for both businesses and individuals.

This guide, along with the resources listed at its conclusion, provides an extensive exploration of the alternatives available to businesses looking to leverage open-source solutions.

This is a work in progress. Please contribute!

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These platforms, providing alternatives to widely-used services like Slack and Discord, offer features ranging from real-time messaging and file sharing, to video conferencing and task management.

• Element ★12911 - A glossy Matrix collaboration client for the web. [TS, GNU Affero General Public License v3.0].
• Mattermost ★36004 - Mattermost is an open source platform for secure collaboration across the entire software development lifecycle.. [TS, Other license].
• RelatedChat ★4792 - Messenger. [Swift, Unknown license].
• Rocket.chat ★45042 - The communications platform that puts data protection first. [TS, Other license].
• Spacebar ★6617 - 📬 Spacebar is a free open source selfhostable discord compatible communication platform. [GNU Affero General Public License v3.0].
• Zulip ★24959 - Zulip server and web application. Open-source team chat that helps teams stay productive and focused. [🐍, Apache License 2.0].

The modern workplace often spans cities, countries, and even continents, making effective virtual communication tools essential. These alternatives to popular services such as Zoom, Webex, Google Meet, Skype, etc., offer features like video and audio calls, screen sharing, virtual meetings, and webinars.

• BigBlueButton ★9065 - Complete open source web conferencing system. [JS, GNU Lesser General Public License v3.0].
• Element Call ★926 - Group calls powered by Matrix. [TS, GNU Affero General Public License v3.0].
• Galene ★1275 - The Galène videoconference server. [Go, MIT License].
• Jitsi Meet ★28903 - Jitsi Meet - Secure, Simple and Scalable Video Conferences that you use as a standalone app or embed in your web application. [TS, Apache License 2.0].

Self-hosted tools that record meetings, produce transcripts and summaries, and keep the original recording.

• Botik ★3 - Self-hosted Discord meeting assistant that records voice calls, posts transcripts and summaries, and answers questions about the meeting. [TS, Apache License 2.0].

Knowledge is the cornerstone of any successful organization, and managing it effectively is crucial. This category focuses on platforms that provide a means for businesses and individuals to store, organize, and share information effectively. These alternatives to Notion - a popular collaboration platform - offer users a versatile and interactive environment for creating, managing, and sharing digital content. From taking notes, tracking tasks, managing projects to creating an internal wiki, these FOSS options provide an array of features that support diverse knowledge management needs while aligning with the principles of openness, flexibility, and community-oriented development.

• AFFiNE ★66733 - There can be more than Notion and Miro. AFFiNE(pronounced [ə‘fain]) is a next-gen knowledge base that brings planning, sorting and creating all together. Privacy first, open-source, customizable and ready to use. [TS, Other license].
• AppFlowy ★68870 - Bring projects, wikis, and teams together with AI. AppFlowy is the AI collaborative workspace where you achieve more without losing control of your data. The leading open source Notion alternative. [Dart, GNU Affero General Public License v3.0].
• BookStack ★18539 - A platform to create documentation/wiki content built with PHP & Laravel. [PHP, MIT License].
• MediaWiki ★5020 - 🌻 The collaborative editing software that runs Wikipedia. Mirror from https://gerrit.wikimedia.org/g/mediawiki/core. See https://mediawiki.org/wiki/Developer_access for contributing. [PHP, Other license].
• MoinMoin ★365 - MoinMoin Wiki Development (2.0+), unstable, for production please use 1.9.x. [🐍, Other license].
• XWiki ★1227 - The XWiki platform. [☕️, GNU Lesser General Public License v2.1].

More:

• WikiMatrix - Compare them all. (WikiMatrix helps you compare the features of many different Wikis in a comfortable side-by-side table.).
• List of wiki software on Wikipedia.
• List of Wiki Engines ow C2. (Exhaustive list of wiki engines, including long-dead ones, with a short description of each one).

These tools are designed to help individuals maintain control over their personal knowledge sphere. These platforms, offering an alternative to the popular Evernote service, enable users to record thoughts, capture information from various sources, and organize these snippets of knowledge in a way that best suits their unique cognitive and workflow preferences.

• Joplin ★54146 - Joplin - the privacy-focused note taking app with sync capabilities for Windows, macOS, Linux, Android and iOS. [TS, Other license].
• Logseq ★41758 - A privacy-first, open-source platform for knowledge management and collaboration. Download link: http://github.com/logseq/logseq/releases. roadmap: http://trello.com/b/8txSM12G/roadmap. [Clojure, GNU Affero General Public License v3.0].
• NoteGen ★12406 - A local-first Markdown note-taking app that captures scattered information and organizes it into structured notes with AI. [TS/Rust, GNU General Public License v3.0].
• Notesnook ★13872 - A fully open source & end-to-end encrypted note taking alternative to Evernote. [TS, GNU General Public License v3.0].
• SiYuan ★42209 - A privacy-first, self-hosted, fully open source personal knowledge management software, written in typescript and golang. [TS, GNU Affero General Public License v3.0].
• qnote - Minimal frameless notepad for Linux with Markdown preview, real PDF export via Typst, OCR, and automatic version history. Built with Tauri 2 (Rust). Available on AUR. [Rust/TS, MIT].

The way we organize and manage our tasks has a significant impact on productivity, and so called "Kanban boards" have proven to be a powerful tool in this regard, by facilitating the visual management of work using the Kanban methodology. These alternatives to Trello offer features such as task cards, customizable boards, and progress tracking that help individuals and teams visualize workflow, manage work-in-progress, and enhance overall productivity.

• Focalboard ★25989 - Focalboard is an open source, self-hosted alternative to Trello, Notion, and Asana. [TS, Other license].
• Kanboard ★9528 - Kanban project management software. [PHP, MIT License].
• Planka ★11758 - The realtime kanban board for workgroups built with React and Redux. [JS, GNU Affero General Public License v3.0].
• WeKan ★20892 - The Open Source kanban (built with Meteor). Keep variable/table/field names camelCase. For translations, only add Pull Request changes to wekan/i18n/en.i18n.json , other translations are done at https://app.transifex.com/wekan/wekan only. [JS, MIT License].
• Super Productivity ★18247 - Advanced todo list app with integrated timeboxing, time tracking, and Jira/GitHub/GitLab integration. [TS, MIT License].
• MonoMap - Keyboard-first, local-first mind map and kanban board web app that runs entirely in the browser. [TypeScript, MIT License].

Self-hostable alternatives to Calendly and similar scheduling tools, letting individuals and teams share their availability and accept bookings without vendor lock-in.

• Tymeslot ★123 - Open-source meeting scheduling platform. Share your availability and let guests book time with you. [Elixir, AGPL-3.0].

• Aster Mail - "Quantum-safe end-to-end encrypted email. Alternative to Gmail, Proton Mail." [AGPL-3.0]

• OpenPost ★17 - Self-hosted social publishing tool for preparing, scheduling, and tracking posts across multiple networks. [Go, GNU Affero General Public License v3.0].

• Crater ★8273 - Open Source Invoicing Solution for Individuals & Businesses. [PHP, GNU Affero General Public License v3.0].
• Invoice Ninja ★9618 - A source-available invoice, quote, project and time-tracking app built with Laravel. [PHP, Other license].
• SolidInvoice ★870 - Simple and elegant invoicing solution. [PHP, MIT License].

• Open Source POS ★4371 - Web-based point of sale software for stores, with inventory, reporting and CodeIgniter/MySQL deployment. [PHP, Other license].
• NexoPOS ★1249 - Laravel-based POS system with Vue.js, Tailwind CSS, inventory management, sales processing, customer records, reports and modular extensions. [PHP, GNU General Public License v3.0].
• Posnic POS ★3 - Offline-first open source POS and billing software for retail shops and restaurants, with desktop packages, self-hosted setup and optional cloud services. Website: https://www.posnic.com/. [JS, GNU Affero General Public License v3.0].

• Dolibarr ★4200 - ERP, CRM, POS, RH
• ERP5 ★206 - ERP5 Open Source ERP/CRM/KM. (Mirror of https://lab.nexedi.com/nexedi/erp5 ; Please submit patches and issues there). [JS, Unknown license].
• IDURAR ERP CRM ★8276 - Free Open Source ERP CRM Accounting Invoicing Software | Node Js React. [JS, GNU Affero General Public License v3.0].
• Odoo ★49816 - Odoo. Open Source Apps To Grow Your Business. [🐍, Other license].
• OpenBooks ★5 - Mid-market open-source accounting/ERP (multi-entity, job costing, approvals, audit trail). [TS, GNU Affero General Public License v3.0].

• Customermates ★223 - Open-core CRM with native MCP, REST, webhooks and a separate n8n community integration; self-hostable with Docker Compose. [TS, AGPL-3.0-only core; commercial server components in ee/].
• SuiteCRM ★5334 - SuiteCRM - Open source CRM for the world. [PHP, GNU Affero General Public License v3.0].
• EspoCRM ★2846 - EspoCRM – Open Source CRM Application. [PHP, GNU Affero General Public License v3.0].
• Warpdrive ★2 - Self-hosted CRM for business development: sales pipeline, deal workspace, contacts, and two-way Gmail sync. Alternative to Pipedrive. [TS, MIT License].

Tools that turn product-usage data into buying, expansion, and churn signals and route the warmest accounts to sales. Alternatives to proprietary PLG-signal platforms such as Pocus and Common Room.

• Beton Inspector ★30 - Open-source revenue intelligence that connects PostHog product usage to your CRM (Attio/HubSpot/Zoho/Pipedrive) and auto-detects buying, expansion, and churn signals. [TS, GNU Affero General Public License v3.0].

Platforms for collecting, organizing, and prioritizing customer feedback, feature requests, and ideas. These tools help product teams understand user needs and build better products.

• Quackback ★33 - Open-source customer feedback platform with public boards, roadmaps, and changelogs. [TS, GNU Affero General Public License v3.0].

• OffPDF - Offline desktop PDF toolkit with 23 tools for editing, converting, organizing, OCR, and related document tasks. Files stay on the device. [Rust/TS, MIT].

• Alfresco ★200 - Alfresco Content Application. [TS, GNU Lesser General Public License v3.0].
• Nuxeo ★701 - Content management platform to build modern business applications. [☕️, Apache License 2.0].
• OpenKM ★840 - OpenKM is a Open Source Document Management System. [☕️, GNU General Public License v2.0].
• LogicalDOC ★136 - LogicalDOC Community open source document management system https://www.logicaldoc.com. [☕️, GNU Lesser General Public License v3.0].
• Mayan EDMS - Free Open Source DMS (document management system).

• Aural ★150 - Open-source, self-hostable AI interview platform for voice, chat, and video interviews. [TS, MIT License].
• FreeATS ★43 - . [💎, MIT License].

• Wordpress ★20984 - WordPress, Git-ified. This repository is just a mirror of the WordPress subversion repository. Please do not send pull requests. Submit pull requests to https://github.com/WordPress/wordpress-develop and patches to https://core.trac.wordpress.org/ instead. [PHP, Other license].
• Ghost ★52242 - Independent technology for modern publishing, memberships, subscriptions and newsletters. [JS, MIT License].
• YunCMS ★0 - Self-hosted MySQL CMS and REST backend with a React Studio, RBAC, Files, extensions and optional MCP. [JS, MIT License]. Website: Yunsoft.

More:

• List of content management systems on Wikipedia (not all open source)

• btw ★1090 - Open source Medium alternative- set up your personal blog in minutes. [JS, GNU General Public License v3.0].
• WriteFreely ★5116 - A clean, Markdown-based publishing platform made for writers. Write together and build a community. [Go, GNU Affero General Public License v3.0].

• Silex ★2741 - Free/libre, online tool for visually creating static sites with dynamic data. No vendor lock-in, self-hosted, desktop version available. [TS, GNU Affero General Public License v3.0].

• ExperimentFlow - A/B testing and AI personalisation platform for optimizing web experiences and conversion rates.

• Matomo ★21380 - Empowering People Ethically 🚀 — Matomo is hiring! Join us → https://matomo.org/jobs Matomo is the leading open-source alternative to Google Analytics, giving you complete control and built-in privacy. Easily collect, visualise, and analyse data from websites & apps. Star us on GitHub ⭐️ – Pull Requests welcome!. [PHP, GNU General Public License v3.0].
• Plausible ★24491 - Simple, open source, lightweight (< 1 KB) and privacy-friendly web analytics alternative to Google Analytics. [💧, GNU Affero General Public License v3.0].
• Prisme Analytics ★124 - 💎 An Open Source, privacy-focused and progressive analytics service. [Go, GNU Affero General Public License v3.0].
• Shynet ★3131 - Modern, privacy-friendly, and detailed web analytics that works without cookies or JS. [🐍, Apache License 2.0].
• Umami ★35907 - Umami is a simple, fast, privacy-focused alternative to Google Analytics. [TS, MIT License].

• 11ty ★19530 - A simpler site generator. Transforms a directory of templates (of varying types) into HTML. [JS, MIT License].
• Hugo ★87346 - The world’s fastest framework for building websites. [Go, Apache License 2.0].
• Jekyll ★51468 - 🌐 Jekyll is a blog-aware static site generator in Ruby. [💎, MIT License].
• Lektor ★3926 - The lektor static file content management system. [🐍, BSD 3-Clause "New" or "Revised" License].
• Pelican ★13262 - Static site generator that supports Markdown and reST syntax. Powered by Python. [🐍, GNU Affero General Public License v3.0].
• Zola ★16799 - A fast static site generator in a single binary with everything built-in. https://www.getzola.org. [🦀, MIT License].

More:

• A List of Static Site Generators for Jamstack Sites
• Awesome Static Web Site Generators ★3662 - A curated list of static web site generators. [Creative Commons Zero v1.0 Universal].

These tools provide a ready-made foundation for building SaaS applications, offering built-in authentication, billing, user management, and other common SaaS features out of the box. They serve as alternatives to proprietary boilerplates like ShipFast, Supastarter, and SaaS Pegasus.

• LastSaaS ★70 - Open-source SaaS platform and boilerplate with built-in authentication, Stripe billing, user management, and admin dashboard. [Go, MIT License].

• Abilian Hop3 ★16 - Hop3 - Open source platform as a service: deploy and manage your applications seamlessly. [🐍, Other license].
• Abilian Nua ★39 - Open source PaaS and application marketplace. [🐍, GNU Affero General Public License v3.0].
• CapRover ★14941 - Scalable PaaS (automated Docker+nginx) - aka Heroku on Steroids. [TS, Other license].
• Coolify ★52388 - An open-source & self-hostable Heroku / Netlify / Vercel alternative. [PHP, Apache License 2.0].
• Dokku ★31924 - A docker-powered PaaS that helps you build and manage the lifecycle of applications. [Shell, MIT License].
• France Nuage ★54 - Sovereign open-source cloud platform: managed hosting of open-source apps and S3-compatible storage. [TS, Server Side Public License v1].
• Peon ★97 - Open-source self-hostable Docker PaaS (Vercel/Heroku alternative) with project RBAC, audit logs, and MCP. [TS, MIT License].

• Janssen ★617 - The Janssen Project maintains open source IAM components, featuring Agama for identity orchestration, and the Cedarling, a WASM or embedded policy evaluation engine. [☕️, Apache License 2.0].
• Keycloak ★33633 - Open Source Identity and Access Management For Modern Applications and Services. [☕️, Apache License 2.0].
• Logto ★11819 - 🧑‍🚀 The better auth and identity infrastructure and the open-source alternative to Auth0. No framework restrictions. [TS, Mozilla Public License 2.0].
• SuperTokens ★14990 - Open source alternative to Auth0 / Firebase Auth / AWS Cognito. [☕️, Other license].
• Authgear ★1580 - Authgear is an open-source Auth0/Clerk alternative for all of your consumer authentication needs. Get started in 5 minutes to integrate passwordless login, passkeys, 2FA, and enterprise-grade security into your applications. It supports modern authentication protocols OIDC and SAML. It features a web portal for user management and setting up authentication/authorization configurations. [☕️, Apache License 2.0]

• Mellisearch ★56837 - A lightning-fast search engine API bringing AI-powered hybrid search to your sites and applications. [🦀, MIT License].
• Sonic ★21176 - 🦔 Fast, lightweight & schema-less search backend. An alternative to Elasticsearch that runs on a few MBs of RAM. [🦀, Mozilla Public License 2.0].
• Tantivy ★14812 - Tantivy is a full-text search engine library inspired by Apache Lucene and written in Rust. [🦀, MIT License].
• Typesense ★25464 - Open Source alternative to Algolia + Pinecone and an Easier-to-Use alternative to ElasticSearch ⚡ 🔍 ✨ Fast, typo tolerant, in-memory fuzzy Search Engine for building delightful search experiences. [C++, GNU General Public License v3.0].

• OpenPaths - Open source model router with universal API for LLMs. Route requests across multiple AI providers with a single unified endpoint.

• Appwrite ★55406 - Build like a team of hundreds_. [TS, BSD 3-Clause "New" or "Revised" License].
• Nhost ★9117 - The Open Source Firebase Alternative with GraphQL. [TS, MIT License].
• Supabase ★99847 - The open source Firebase alternative. Supabase gives you a dedicated Postgres database to build your web, mobile, and AI applications. [TS, Apache License 2.0].
• Manifest ★4143 - 🦚 The 1-file backend. [TS, MIT License].

• Apprise ★16223 - Apprise - Push Notifications that work with just about every platform!. [🐍, BSD 2-Clause "Simplified" License].
• Novu ★38746 - The open-source notification Inbox infrastructure. E-mail, SMS, Push and Slack Integrations. [TS, Other license].
• ntfy ★29491 - Send push notifications to your phone or desktop using PUT/POST. [Go, Apache License 2.0].

• Hook0 ★1406 - Open-source webhook server written in Rust that helps you provide webhooks to your users. [🦀, Server Side Public License v1].

• NSL.SH (Source) ★70 - Distributed domain routing for self-hosted services with automatic HTTPS, working behind NAT. Uses WireGuard and Caddy. [TS/Lua, MIT License].

• Graylog ★7990 - Free and open log management. [☕️, Other license].

• Coroot ★7534 - Coroot is an open-source APM & Observability tool, a DataDog and NewRelic alternative. Metrics, logs, traces, continuous profiling, and SLO-based alerting, supercharged with predefined dashboards and inspections. [Go, Apache License 2.0].
• hyperdx ★9404 - Resolve production issues, fast. An open source observability platform unifying session replays, logs, metrics, traces and errors powered by Clickhouse and OpenTelemetry. [TS, MIT License].
• signoz ★26329 - SigNoz is an open-source observability platform native to OpenTelemetry with logs, traces and metrics in a single application. An open-source alternative to DataDog, NewRelic, etc. 🔥 🖥. 👉 Open source Application Performance Monitoring (APM) & Observability tool. [TS, Other license].
• Sentry ★43468 - Developer-first error tracking and performance monitoring. [🐍, Other license].
• Telemetry Tracker ★32 - Open-source, self-hostable error tracker for side projects and small teams, with grouped errors, source maps and alerts. [TS, MIT License].
• KubeStellar Console ★66 - Multi-cluster Kubernetes dashboard with real-time observability, compliance monitoring, and AI-powered operations across edge and cloud clusters. CNCF project. [Go/TS, Apache License 2.0].
• VictoriaLogs ★1904 - Fast and easy to use database for logs, which can efficiently handle terabytes of logs. [Go, Apache License 2.0].
• VictoriaMetrics ★17055 - Fast, cost-effective monitoring solution and time series database. [Go, Apache License 2.0].

• Bruin ★1669 - End-to-end data pipeline CLI: data ingestion, SQL and Python transformation, and data quality checks in one tool. [Go, Apache License 2.0].

• Orbit ★47 - Free, realtime task manager with issues, projects, sprints, docs, files and a hosted OAuth MCP server. [TS, Apache License 2.0].
• Bugzilla ★810 - Official repository for the Bugzilla bug tracking system. Report bugs to https://bugzilla.mozilla.org/enter_bug.cgi?product=Bugzilla&format=__default__ . Main website:. [Perl, Mozilla Public License 2.0].
• Plane ★47112 - 🔥 🔥 🔥 Open Source JIRA, Linear, Monday, and Asana Alternative. Plane helps you track your issues, epics, and cycles the easiest way on the planet. [TS, GNU Affero General Public License v3.0].
• Redmine ★5920 - Mirror of redmine code source - Official Subversion repository is at https://svn.redmine.org/redmine - contact: @vividtone or maeda (at) farend (dot) jp. [💎, Other license].
• Taiga ★554 - Taiga is a free and open-source project management for cross-functional agile teams. [🐍, Mozilla Public License 2.0].

• Forgejo ★2200 - Forgejo is a self-hosted lightweight software forge maintained by an inclusive community under the umbrella of Codeberg e.V., a registered non-profit association based in Berlin, Germany. [Go, GNU General Public License v3.0].
• Gitea ★54595 - Git with a cup of tea! Painless self-hosted all-in-one software development service, including Git hosting, code review, team collaboration, package registry and CI/CD. [Go, MIT License].
• Gitlab ★24285 - GitLab CE Mirror | Please open new issues in our issue tracker on GitLab.com. [💎, Other license].
• Gogs ★47578 - Gogs is a painless self-hosted Git service. [Go, MIT License].
• Pagure ★223 - pagure is a light-weight git-centered forge based on pygit2. (MIRROR). [🐍, GNU General Public License v2.0].
• Sourcehut - This suite of open source tools is the software development platform you've been waiting for.

• Buildbot ★5441 - Python-based continuous integration testing framework; your pull requests are more than welcome!. [🐍, GNU General Public License v2.0].
• Drone ★34191 - Harness Open Source is an end-to-end developer platform with Source Control Management, CI/CD Pipelines, Hosted Developer Environments, and Artifact Registries. [Go, Apache License 2.0].
• Jenkins ★25144 - Jenkins automation server. [☕️, MIT License].

• Gerrit ★1163 - Gerrit Code Review - (mirror of https://gerrit.googlesource.com/gerrit). [☕️, Apache License 2.0].
• Review Board ★1698 - An extensible and friendly code review tool for projects and companies of all sizes. [🐍, MIT License].

This it not the first list of free / open source software. Here are some other lists:

• EuroStack Directory - A curated list of open-source alternatives to popular SaaS products, with a focus on European solutions.
• Awesome-Selfhosted ★282926 - A list of Free Software network services and web applications which can be hosted on your own servers. [Other license].
• AFS ONE - Free Software Publisher Directory.
• Awesome Free Software ★11 - Your "yellow pages" of Enterprise Free Software Publishers, their products and success cases. [Unknown license].
• Awesome open-source alternatives to SaaS ★18940 - Awesome list of open-source startup alternatives to well-known SaaS products 🚀. [🐍, MIT License].
• Guide des solutions open source (in French)
• SILL - Catalogue de référence de logiciels libres recommandés pour l'ensemble de l'administration (in French)
• Comptoir du Libre (in French)
• Awesome F/OSS - "Explore the universe of awesome Free and Open Source software."
• Awesome Free Software ★2659 - Curated list of free as in freedom software. [Creative Commons Zero v1.0 Universal].
• Open-source alternatives
• PickYourTech - Catalog of open-source projects, categorized with detailed metadata and open-source alternatives to popular SaaS platforms.
• os-alt - Directory of paid SaaS with strictly self-hostable open-source alternatives, listing setup-time score, monthly self-host cost estimate, and migration sketch per tool.

• IndieStack - Directory of indie-built SaaS alternatives across 100+ categories.