Sites like xmpp.net

Gajim, a free desktop chat app for the XMPP messaging protocol, with synchronized chats across devices

Converse, an open-source web-based XMPP chat client and embeddable messaging library with documentation for developers

F-Droid is an app store and distribution platform for free and open source Android apps

Cheogram is a messaging service that connects telephone SMS and open chat networks such as XMPP and Matrix into one app

Despair Labs, a personal blog by Rob Norris on computing, OpenZFS open source work, and conference presentations

Psi Instant Messenger, a free open-source instant messaging application for the XMPP network on Windows, Linux and macOS

Movim, a decentralized social network and chat platform built on the XMPP protocol, for communication across devices

Stéphane Graber's blog on the Incus and LXC container projects, with release announcements and notes from Ubuntu and upstream work

RigReference.com is a database of amateur radio equipment with reviews, manuals, prices, images, solar conditions and user-built shack pages

UnifiedPush is an open-source, decentralized push notification system letting app developers and users choose their own notification service

Personal home page of Eric S. Raymond hosting his open-source software, FAQs, essays and the Retrocomputing Museum

Matrix.org, the home of an open, decentralised network for secure chat and communication, run by the Matrix project

mailcow: dockerized news blog from The Infrastructure Company GmbH on the mailcow open-source mail server suite, with release updates

A Go software co-op's collection of XMPP libraries and tools, including the mellium.im/cli and mellium.im/xml packages

unsigned.io is a personal site by an independent developer covering Reticulum mesh networking, LXMF messaging, and open-source RNode radio hardware

Pleroma, a lightweight social networking server software project for the Fediverse, with a news page and blog

BorgBackup, an open-source deduplicating backup archiver with compression and authenticated encryption, with documentation, release series and support pages

Branchable is a hosting service for Ikiwiki-powered websites, wikis and blogs built on Git

A free, open-source, non-profit web search engine called Mwmbl, with its own crawled index and public statistics

A free, extensible text-based IRC chat client, WeeChat, developed by a volunteer group of open-source programmers

Accrescent, an alpha-stage private and secure Android app store with a developer console and documentation

The Battle for Wesnoth is an open source, turn-based fantasy strategy video game, with its project's developer documentation and release notes

OpenStore is an open source app store for installing and publishing apps on the Ubuntu Touch mobile operating system

A Lemmy federated news server run by the developer of the Voyager app, for its users and contributors

PussTheCat.org is a non-profit site offering ad-free privacy-focused open-source services, game servers and a SearXNG search instance

A German-language collection of open-source software services run by a private individual, ad-free and funded by donations

OpenRepos.net is a community repository of third-party applications for Linux mobile platforms such as Sailfish OS and Nemo Mobile

Mysk Blog: independent cybersecurity and mobile app privacy research posts, including WebKit leak and macOS sandbox vulnerability disclosures, by Mysk

A German personal site by Andreas Itzchak Rehberg on Android books and coaching, plus Oracle database administration tips and services

A blog by Steve on MQTT messaging protocol and networking technologies, with tutorials for IoT engineers and hobbyists

Stephen Paul Weber's personal website: blog essays on technology and inequality, software projects, standards work, and his resume

The official home of Xfce, a lightweight desktop environment for UNIX-like operating systems, with release news and blog posts

Syncthing, an open-source continuous file synchronisation tool, with project donation and foundation information pages

Dave Lee's personal blog and homepage covering Linux, Android, podcasting, amateur radio, music and application security

A free, open-source Android-based mobile operating system for various devices, with release changelogs and news from its team

Librem One, a subscription bundle of privacy-focused online services and apps from the company Purism, with a Mastodon social server

YaCy free peer-to-peer search engine software for local, intranet and decentralized web indexing, with its documentation and FAQ

A German-language podcast radio station from Leipzig producing journalistic podcasts, livestreams and music programmes, led by Christian Bollert

Nextcloud, an open source self-hosted platform for file sharing and online collaboration as a Microsoft 365 alternative