👥 Social MediaDE
Mastodon
German-founded, AGPL-licensed federated social platform where independent servers interoperate via ActivityPub. Mastodon removes ad-driven ranking by default, while privacy and moderation practices depend on the instance you choose.
open-sourcesocial-mediafederated
🖥️ VirtualizationAT
Proxmox Virtual Environment
Austrian open-source server virtualization platform combining KVM hypervisor and LXC containers in a single solution. Developed by Proxmox Server Solutions GmbH (Vienna) since 2005, with full source code available at git.proxmox.com. Enterprise-ready with high-availability clustering, software-defined storage, and integrated backup solutions.
open-sourcevirtualizationhypervisor
🖥️ VirtualizationUS
QEMU
QEMU is a free, open-source machine emulator and virtualizer that can run full guest operating systems across many CPU architectures or execute foreign-architecture user-space binaries. It supports full-system emulation, hardware-assisted virtualization with KVM/Xen, and disk-image tooling such as qemu-img, making it useful for developers, infrastructure teams, and security testing workflows that need portable self-hosted virtualization.
open-sourcevirtualizationemulation
🧑💻 Version Control ServicesCH
Radicle
Open-source peer-to-peer code collaboration stack built on Git. Unlike centralized platforms, there is no single entity controlling the network — repositories are replicated across peers in a decentralized manner, giving users full control of their data. Features include cryptographic identities, local-first design, and a modular stack with CLI, TUI, and web interface. Operated by Better Internet Foundation, a Swiss non-profit.
open-sourceversion-controldevops
🔍 Search EngineFR
SearXNG
Free and open-source metasearch engine forked from searx in 2021. Aggregates results from up to 244 search services without tracking or profiling users. Self-hostable via Docker or manual installation with ~70 public instances available. Developed by an international community with European roots (fork of searx, originally created by Hungarian developer Adam Tauber).
open-sourcesearch-engineprivacy
💬 MessagingCH
Session
End-to-end encrypted messenger that protects your private data. A decentralized app designed, built, and operated by a global community of privacy experts, using onion routing to hide IP addresses.
open-sourcemessaginge2ee
📋 Project ManagementDE
Zammad
German open-source helpdesk and customer support system with multi-channel communication (email, chat, phone, WhatsApp, Telegram). Developed by Zammad GmbH in Berlin, with source code owned by the Zammad Foundation. Offers both SaaS and self-hosted deployment options.
open-sourcehelpdesksupport
📄 Office SuiteDE
openDesk
German government-backed open-source office and collaboration suite developed by ZenDiS (Centre for Digital Sovereignty). openDesk integrates Collabora Online for documents, Nextcloud for file storage, Open-Xchange for email/calendar, Element for messaging, Jitsi for video conferencing, and OpenProject for task management into a single sovereign workplace platform. Primarily aimed at public administration, but available to private individuals as well via the community edition.
open-sourceoffice-suitecollaboration
📲 2FA AuthenticatorsPL
2FAS Auth
Open-source two-factor authentication app supporting Android, iOS, and a browser extension for autofilling codes. Developed by a Polish team (Emphie Solutions, Gliwice) and open-sourced under GPL-3.0, though graphics are separately licensed. Operated by dual entities: 2FAS Sp. z o.o. (Poland) and 2FAS Inc. (USA).
open-source2faauthenticator
🔐 Password ManagerNL
AliasVault
Privacy-first password manager with built-in email aliasing. End-to-end encrypted with zero-knowledge architecture. Self-hostable via Docker. Founded by Dutch developer with 15 years privacy tool experience.
open-sourcepassword-managerencryption
🗺️ Maps & NavigationOSS
CoMaps
Community-driven privacy-focused offline maps app forked from Organic Maps. Built by former Organic Maps contributors following governance concerns. Works completely offline with no tracking, no data collection, and no ads. Open source under Apache 2.0, funded by community donations.
open-sourcemapsprivacy
💬 MessagingDE
Conversations
Free and open-source Jabber/XMPP client for Android smartphones. Supports end-to-end encryption with OMEMO and OpenPGP, voice and video calls, file transfers, group chats, and location sharing. Available on Google Play and F-Droid. Developed by German freelance developer Daniel Gultsch.
open-sourcemessagingfederated
🌐 BrowserIT
Cromite
Cromite is a Bromite fork with built-in ad blocking and privacy features.
open-sourcebrowserprivacy
👥 Social MediaUS
Discourse
US-based fully open-source community discussion platform with features for forums, knowledge bases, and real-time chat. Available as managed hosting or self-hosted, with full source code on GitHub under GPL-2.0.
open-sourcesocial-mediaforum
🏢 Cloud & HostingOSS
Dokku
Dokku is a self-hosted open-source platform-as-a-service that lets developers deploy Heroku-style applications to a server they control via Git push. It runs on a single host, uses Docker and plugins for app management, and targets teams that want a lightweight, production-ready PaaS without depending on a US cloud vendor.
open-sourceself-hostedpaas
📦 OtherPL
Food You
Food You is a free, open-source, privacy-focused Android food diary and nutrition tracker. It stores user data locally, requires no account, supports calorie, macro, vitamin and mineral tracking, and can retrieve nutrition data from Open Food Facts, USDA FoodData Central, and the Swiss Food Composition Database.
nutritioncalorie-trackerfood-diary
🔑 Identity & Access ManagementUS
FreeIPA
FreeIPA is a self-hosted identity and access management platform for Linux and UNIX environments. It centralizes user, host, policy, DNS, certificate, and Kerberos-based single sign-on management through a web UI and command-line tools, and it is aimed at organizations that want an open-source alternative to Microsoft Active Directory with strong Linux integration and AD trust/interoperability.
open-sourceself-hostedldap
🔑 Identity & Access ManagementUS
Keycloak
Open-source Identity and Access Management solution providing single sign-on, user federation, and fine-grained authorization. As a CNCF incubating project, Keycloak offers SAML, OAuth 2.0, and OpenID Connect support with a focus on cloud-native deployments. Originally created by Red Hat, now community-maintained under CNCF governance.
open-sourceiamsso
📝 Note-TakingDE
Linwood Butterfly
Linwood Butterfly is a free, open-source note-taking app built around an infinite canvas. Users can draw, add rich text or markdown, import and export images, PDFs, and SVGs, and organize notes with pages, areas, and waypoints. It runs on Android, Windows, Linux, and the web, works offline, and can store data locally or through WebDAV, making it suitable for students, handwritten note takers, and visual note-taking workflows.
open-sourcecross-platformoffline
☁️ Cloud StorageDE
LocalSend
Open-source cross-platform file sharing app that allows secure transfer between nearby devices over local network without internet. End-to-end encrypted, no account required. Developed by German individual developer Tien Do Nam.
open-sourcefile-sharingairdrop-alternative
🛡️ Privacy ToolsUS
LuLu
LuLu is a free, fully open-source macOS firewall from Objective-See that alerts on new outgoing network connections and lets users allow or block them with persistent or temporary rules. It also supports profiles, block/allow lists, and an integrated network monitor, making it suitable for Mac users who want local privacy and traffic-control tooling without a required cloud service.
open-sourcemacosfirewall
🎮 Game Stores & LaunchersOSS
Lutris
Lutris is an open-source gaming platform for Linux that installs and launches games through emulators, compatibility layers, and connected game libraries.
📝 Note-TakingEU
Marknote
Marknote is a free KDE note-taking app for creating rich text notes and organizing them into notebooks. It stores notes as Markdown files in the user's Documents folder, supports notebook customization with icons and accent colors, and is aimed at users who want a local-first, open-source alternative to cloud-centered note apps.
open-sourcefossmarkdown
☁️ Cloud StorageDE
Nextcloud
Self-hosted, open-source cloud platform offering file sync, collaboration, and office editing — trusted by the German and French governments. Nextcloud uses AGPLv3 and supports end-to-end encryption through dedicated encrypted folders, while default server-side encryption remains admin-accessible.
open-sourcecloud-storageself-hosted