Software

Bookmark and archive manager to store your useful links. ([Source Code](https://github.com/linkwarden/linkwarden))

Save the precious readable content of web pages you like and want to keep forever. See it as a bookmark manager and a read later tool. ([Source Code](https://codeberg.org/readeck/readeck), [Clients](https://codeberg.org/readeck/browser-extension))

Sync and manage your browser bookmarks from Edge, Firefox and Chromium. ([Clients](https://codeberg.org/Offerel/SyncMarks-Extension))

Lightweight CalDAV and CardDAV server based on sabre/dav. ([Source Code](https://github.com/sabre-io/Baikal))

Server for calendar sharing (CalDAV) that uses a PostgreSQL database as a data store. ([Source Code](https://gitlab.com/davical-project/davical))

Manage my Damn Life (MMDL) is a front end for managing your CalDAV tasks and calendars. ([Source Code](https://github.com/intri-in/manage-my-damn-life-nextjs))

Simple calendar and contact server with extremely low administrative overhead. ([Source Code](https://github.com/Kozea/Radicale))

CardDAV, CalDAV, and WebDAV framework and server. ([Source Code](https://github.com/sabre-io/dav))

Realtime server for reliable two-way communication over WebSockets, Server-sent events, etc. ([Demo](https://demo.anycable.io), [Source Code](https://github.com/anycable/anycable))

Language-agnostic real-time messaging (Websocket or SockJS) server. ([Demo](https://github.com/centrifugal/centrifugo#demo), [Source Code](https://github.com/centrifugal/centrifugo))

Peer-to-peer chat app that is serverless, decentralized, and ephemeral. ([Source Code](https://github.com/jeremyckahn/chitchatter))

Simple, fast, and reliable chat server powered by Matrix. ([Source Code](https://gitlab.com/famedly/conduit))

Fully-featured Matrix client for Web, iOS & Android. ([Source Code](https://github.com/element-hq/element-web))

Whistleblowing software enabling anyone to easily set up and maintain a secure reporting platform. ([Demo](https://demo.globaleaks.org), [Source Code](https://github.com/globaleaks/globaleaks-whistleblowing-software))

Software framework for decentralized, peer-to-peer networking. ([Source Code](https://gnunet.org/git/))

Notification server with Android and CLI clients (alternative to PushBullet). ([Source Code](https://github.com/gotify/server), [Clients](https://github.com/gotify/android))

Anonymously share files, browse and publish freesites (web sites accessible only through Hyphanet) and chat on forums. ([Source Code](https://github.com/hyphanet/fred))

Universal communication platform which preserves the user's privacy and freedoms. ([Source Code](https://git.jami.net/savoirfairelinux?sort=latest_activity_desc&filter=jami))

Live Support chat for your website. ([Source Code](https://github.com/LiveHelperChat/livehelperchat))

Low-latency, high quality voice/text chat software. ([Source Code](https://github.com/mumble-voip/mumble), [Clients](https://wiki.mumble.info/wiki/3rd_Party_Applications))

Notification infrastructure for developers. ([Source Code](https://github.com/novuhq/novu/))

Push notifications to phone or desktop using HTTP PUT/POST, with Android app, CLI and web app, similar to Pushover and Gotify. ([Demo](https://ntfy.sh/app), [Source Code](https://github.com/binwiederhier/ntfy), [Clients](https://github.com/binwiederhier/ntfy-android))

Share sensitive information securely with self-destructing links that are only viewable once. ([Demo](https://onetimesecret.com), [Source Code](https://github.com/onetimesecret/onetimesecret))

One-Time-Secret sharing platform with a symmetric 256bit AES encryption in the browser. ([Source Code](https://github.com/Luzifer/ots))