Sites like open.mp

CLEO Library, a scripting library and SDK documentation site for running custom scripts in GTA games without modifying game files

PaperMC is an open-source project producing Paper, Velocity and Folia, high-performance Minecraft server software, with news, team pages and Javadocs

Pelican is a free, open-source web control panel for hosting and managing game servers in Docker containers

GeyserMC, a project site offering downloads, API documentation and wiki pages for Geyser, a Java-to-Bedrock Minecraft bridge

MyBB is a free, open source forum software project, with its download, documentation and support community hosted on its own site

Urban Terror, a free multiplayer first-person shooter game and community site with developer news and tournament announcements

Playnite, an open source video game library manager that unifies games from Steam, Epic, GOG and other stores

EngineHub: an open-source collection of Minecraft mods, plugins and tools such as WorldEdit and CraftBook

Flow Launcher, a free open-source quick file search and app launcher tool for Windows, with a plugin directory

A free open-source web-based manager for starting and administering Minecraft servers, with downloads for Docker, Linux and Windows

Pterodactyl is a free, open-source web panel for self-hosting and managing game servers in Docker containers

Prism Launcher: a free open-source Minecraft launcher for managing multiple game instances, accounts and mods, forked from MultiMC

Personal homepage, blog and file archive of Linus Åkesson in Lund, Sweden, with SID music search and demoscene projects

Factorio, a factory-building video game by Wube studio in Prague, with its official news blog of Friday Facts updates

Sponge, an open-source modding API and plugin platform for Minecraft: Java Edition, run by the SpongePowered community project

WinSCP, a free open-source SFTP and FTP client application for Windows file transfers between local and remote computers

LaunchBox, a Windows and Android game launcher and library manager for emulators, DOSBox and PC games

EndeavourOS, a terminal-centric Arch-based Linux distribution project with its own community, news and ISO releases

Vintage Story, a wilderness survival sandbox video game set in a ruined, temporally disturbed world

Rocket.Chat, an open source team chat and collaboration platform for secure, self-hosted government and enterprise communications

Joplin, an open source note-taking app with multimedia notes, web clipping and end-to-end encrypted sync, developed by Laurent

Free open source software for video recording and live streaming, the OBS Studio download and project site

Serebii.net is a fan-run Pokémon news and reference website covering games, anime, GO, LEGO, and event giveaways

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

Alpine Linux, an independent lightweight Linux distribution built on musl libc and busybox, with its release announcements and documentation

Weasel Mods, a forum board for selected Baldur's Gate and Icewind Dale game mods and related news

Tasks.org: documentation and product pages for Tasks, a free open-source Android task management app with CalDAV sync

OpenClaw: an open-source AI assistant project with desktop, mobile and terminal installs, press coverage, privacy and security pages, run by Peter Steinberger

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

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

The official website of the D Programming Language, covering its documentation, downloads, compiler releases, and community resources

A community-run site sharing custom content, mods, stories and archives for life-simming games such as The Sims 1 and 2

The official website of Vue.js, the open-source JavaScript framework for building web user interfaces, with its API reference and documentation

A community database and progress tracker for the game IDOLM@STER Cinderella Girls Starlight Stage, with player profiles, maps and a wiki

A free Japanese learning site with lessons, quizzes and a course, plus Patreon posts, run under the name Marshall's Site

Slow travel and digital nomad blog by Joel and Michelle Hartz, covering cost of living and destination guides abroad