Hound CICommunicationComments on style violations in GitHub pull requests. Supports Coffeescript, Go, HAML, JavaScript, Ruby, SCSS and Swift.Views10viewsFree
GGEO AuditCommunicationSee how ChatGPT, Perplexity & Gemini actually read your sitePH9Product Hunt votesViews10viewsFreemium
CaprineCommunicationThird-party privacy-focused Facebook Messenger app. ![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]GH7.4KGitHub starsViews7viewsOpen Source
CursorCommunicationAI code editor with autocomplete, chat, and coding agent features. ![Freeware][Freeware Icon]Views6viewsFree
HuggingChatCommunicationOpen-source AI chat by Hugging FaceGH10.8KGitHub starsViews6viewsFreeOpen SourceAIChatbot
HHiggsfield SupercomputerCommunicationRun your entire creative pipeline from one chat agentPH71Product Hunt votesViews5viewsFreemium
SimpleX ChatCommunicationThe most private and secure chat and applications platform - now with double ratchet E2E encryption. AGPL-3.0 HaskellGH11.2KGitHub starsViews5viewsOpen Source
Quassel IRCCommunicationDistributed IRC client, meaning that one (or multiple) client(s) can attach to and detach from a central core. ([Source Code](https://github.com/quassel/quassel)) GPL-2.0 C++Views5viewsFree
CConnector.wtfCommunicationPlug Google Ads, Meta & LinkedIn into your AI chat. FreePH76Product Hunt votesViews5viewsFreemium
LitmusCommunicationan email campaign creation platform that, amongst other things, lets you see how HTML emails will appear in a wide variety of email clients.Views5viewsFree
KKeptCommunicationYour AI chats, saved as Markdown locally with no cloudPH110Product Hunt votesViews5viewsFreemium
MMashuPackCommunicationTurn codebases into a clean file for Claude and ChatGPTPH113Product Hunt votesViews5viewsFreemium
OOpenclaw OSCommunicationTurn one-off chats into persistent, usable appsPH111Product Hunt votesViews5viewsFreemium
SSearchad.aiCommunicationRun Apple Search Ads by Chatting with AIPH144Product Hunt votesViews5viewsFreemium
AAEO Audit ProCommunicationOptimize your website for ChatGPT, Perplexity & AI SearchPH4Product Hunt votesViews5viewsFreemium
ZZen ReportsCommunicationSee how much traffic your website gets from ChatGPTPH77Product Hunt votesViews5viewsFreemium
AAutomailCommunicationBYOSMTP email platform — enterprise features from ₹1,199/moPH1Product Hunt votesViews5viewsFreemium
AppriseCommunicationApprise allows you to send a notification to almost all of the most popular notification services available to us today such as: Telegram, Discord, Slack, Amazon SNS, Gotify, etc. MIT Python/Docker/deGH16.7KGitHub starsViews5viewsOpen Source
ReviewdogCommunicationA tool for posting review comments from any linter in any code hosting service.GH9.3KGitHub starsViews5viewsOpen Source
BBeyondCommentsCommunicationTurn YouTube comments into channel growth, in 45 seconds!PH33Product Hunt votesViews5viewsFreemium
MailpileCommunicationA modern, fast web-mail client with user-friendly encryption and privacy features.Views5viewsFree
AAI Visibility Audit ChecklistCommunicationCheck if ChatGPT and AI search engines understand your brandPH24Product Hunt votesViews5viewsFreemium
RRunway AgentCommunicationGenerate edited, sound-designed videos via chatPH167Product Hunt votesViews5viewsFreemium
CChatGPT for Google SheetsCommunication Chat with your spreadsheet, edit cell with natural languagePH126Product Hunt votesViews4viewsFreemium
ttrendos.comCommunicationMonitor which ChatGPT ads show up on your queriesPH5Product Hunt votesViews4viewsFreemium
AsmBBCommunicationFast, SQLite-powered forum engine written in ASM. ([Source Code](https://asm32.info/fossil/asmbb/index)) EUPL-1.2 AssemblyViews4viewsFree
GGliaCommunicationLocal-first AI memory bridge between browser chats and IDEsPH108Product Hunt votesViews4viewsFreemium
DDraftCommunicationCapture AI chats into your knowledge basePH114Product Hunt votesViews4viewsFreemium
PaletteBrainCommunicationAccess the power of ChatGPT across all your Mac applications with the press of a shortcut.Views4viewsFree
PingMeCommunicationSend messages/alerts to multiple messaging platforms & email.GH853GitHub starsViews3viewsOpen Source
linty freshCommunicationParse lint errors and report them to Github as comments on a pull request.GH185GitHub starsViews3viewsOpen Source
mail-archiverCommunicationWeb application for archiving, searching, and exporting emails from multiple accounts (IMAP, M365 or Import). Featuring folder sync, attachment support, mailbox migration and a dashboard. GPL-3.0 DockGH1.9KGitHub starsViews3viewsOpen Source
TinodeCommunicationInstant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots. ([Demo](https://sandbox.tinode.co/), [Source Code](https://github.com/tinode/Views3viewsOpen Source
SyncTubeCommunicationLightweight and very simple to setup CyTube alternative to watch videos with friends and chat. MIT Nodejs/HaxeGH377GitHub starsViews3viewsOpen Source
Atomic ChatCommunicationOpen-source AI chat client for local and cloud models with MCP support. [![Open-Source Software][OSS Icon]](https://github.com/AtomicBot-ai/Atomic-Chat)GH858GitHub starsViews3viewsOpen Source
SparkCommunicationFast email client. For both Mac OS and iOS.![Freeware][Freeware Icon]Views3viewsFree
LangLintCommunicationAutomated translation platform for code comments and docstrings across 20+ file types. Eliminates language barriers in international software collaboration. Supports 100+ language pairs with syntax prViews3viewsOpen Source
CCalling Skills for AI AgentsCommunicationAdd voice and video calling via your coding agentPH116Product Hunt votesViews3viewsFreemium
iRedMailCommunicationFull-featured mail server solution based on Postfix and Dovecot. ([Source Code](https://github.com/iredmail/iRedMail)) GPL-3.0 ShellViews3viewsFree
FFile Generation in GeminiCommunicationGenerate production-ready files directly in your chatViews3viewsFreemium
TalkyardCommunicationCreate a community, where your users can suggest ideas and get questions answered. And have friendly open-ended discussions and chat (Slack/StackOverflow/Discourse/Reddit/Disqus hybrid). ([Demo](httpsViews3viewsFree
RRankings across all App StoresCommunication10 seconds – all posts, reviews, push notificationsViews3viewsFreemium
AAIRankCiteCommunicationTrack where AI mentions your SaaS across Reddit and forumsViews3viewsFreemium
Countly Community EditionCommunicationReal time mobile and web analytics, crash reporting and push notifications platform. ([Source Code](https://github.com/Countly/countly-server)) AGPL-3.0 Nodejs/DockerViews3viewsFree
TextualCommunicationInternet Relay Chat (IRC) client. [![Open-Source Software][OSS Icon]](https://github.com/Codeux-Software/Textual) [![App Store][app-store Icon]](https://apps.apple.com/us/app/telegram/id747648890?platViews3viewsFree
DovecotCommunicationIMAP and POP3 server written primarily with security in mind. ([Source Code](https://github.com/dovecot/core)) MIT/LGPL-2.1 C/debViews3viewsFree
Ech0CommunicationLightweight federated publishing platform focused on personal idea sharing (documentation in Chinese). ([Demo](https://memo.vaaat.com/), [Source Code](https://github.com/lin-snow/Ech0)) AGPL-3.0 DockeViews3viewsFree
ConduitCommunicationA simple, fast, and reliable chat server powered by Matrix. ([Source Code](https://gitlab.com/famedly/conduit)) Apache-2.0 RustViews3viewsFree
NotifoCommunicationMultichannel notification server with support for Email, Mobile Push, Web Push, SMS, messaging and a javascript plugin. MIT C#GH873GitHub starsViews3viewsOpen Source
ElementCommunicationFully-featured Matrix client for Web, iOS & Android. ([Source Code](https://github.com/element-hq/element-web)) Apache-2.0 NodejsViews3viewsFree
HyphanetCommunicationAnonymously share files, browse and publish _freesites_ (web sites accessible only through Hyphanet) and chat on forums. ([Source Code](https://github.com/hyphanet/fred)) GPL-2.0 JavaViews3viewsFree
Live Helper ChatCommunicationLive Support chat for your website. ([Source Code](https://github.com/LiveHelperChat/livehelperchat)) Apache-2.0 PHPViews3viewsFree
PushBitsCommunicationNotification server for relaying push notifications via Matrix, similar to PushBullet and Gotify. ISC GoGH360GitHub starsViews3viewsOpen Source
ShhhCommunicationKeep secrets out of emails or chat logs, share them using secure links with passphrase and expiration dates. MIT PythonGH414GitHub starsViews3viewsOpen Source
SynapseCommunicationServer for [Matrix](https://matrix.org/), an open standard for decentralized persistent communication. ([Source Code](https://github.com/element-hq/synapse)) Apache-2.0 Python/debViews3viewsFree
RetroShareCommunicationSecured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source Code](https://github.com/RetroShare/RetroShare)) GPL-2.0 C++Views3viewsFree
Rocket.ChatCommunicationCommunications platform that puts data protection first (alternative to Gitter.im and Slack). ([Source Code](https://github.com/RocketChat/Rocket.Chat)) MIT Nodejs/Docker/K8SViews3viewsFree
StoatCommunicationStoat is a user-first chat platform built with modern web technologies. ([Source Code](https://github.com/stoatchat/self-hosted)) AGPL-3.0/MIT RustViews3viewsFree
ToxCommunicationDistributed, secure messenger with audio and video chat capabilities. ([Source Code](https://github.com/TokTok/c-toxcore)) GPL-3.0 CViews3viewsFree
DovelCommunicationSMTP server that sends and receives emails according to a simple configuration file, with an optional web interface that you can use to browse your emails. ([Source Code](https://dovel.email/server/trViews3viewsFree
Mail-in-a-BoxCommunicationTurns any Ubuntu server into a fully functional mail server with one command. ([Source Code](https://github.com/mail-in-a-box/mailinabox)) CC0-1.0 ShellViews3viewsFree
MailcowCommunicationMail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration. ([Source Code](https://github.com/mailcow/mailcow-dockerized)) GPL-3.0 DocViews3viewsFree
MailuCommunicationSimple yet full-featured mail server as a set of Docker images. ([Source Code](https://github.com/Mailu/Mailu)) MIT Docker/PythonViews3viewsFree
Stalwart Mail ServerCommunicationAll-in-one mail server with JMAP, IMAP4, and SMTP support and a wide range of modern features. ([Source Code](https://github.com/stalwartlabs/stalwart)) AGPL-3.0 Rust/DockerViews3viewsFree
Cyrus IMAPCommunicationEmail (IMAP/POP3), contacts and calendar server. ([Source Code](https://github.com/cyrusimap/cyrus-imapd)) BSD-3-Clause-Attribution CViews3viewsFree
Courier MTACommunicationFast, scalable, enterprise mail/groupware server providing ESMTP, IMAP, POP3, webmail, mailing list, basic web-based calendaring and scheduling services. ([Source Code](https://www.courier-mta.org/repViews3viewsFree
EmailRelayCommunicationA small and easy to configure SMTP and POP3 server for Windows and Linux. ([Source Code](https://sourceforge.net/p/emailrelay/code/HEAD/tree/)) GPL-3.0 C++Views3viewsFree
OpenSMTPDCommunicationSecure SMTP server implementation from the OpenBSD project. ([Source Code](https://github.com/OpenSMTPD/OpenSMTPD/)) ISC C/debViews3viewsFree
MailmanCommunicationManage electronic mail discussion and e-newsletter lists. ([Source Code](https://gitlab.com/mailman/)) GPL-3.0 PythonViews3viewsFree
Glowing BearCommunicationA web frontend for WeeChat. ([Demo](https://www.glowing-bear.org)) GPL-3.0 NodejsGH971GitHub starsViews3viewsOpen Source
SquirrelMailCommunicationAnother browser-based IMAP client. ([Source Code](https://sourceforge.net/p/squirrelmail/code/HEAD/tree/)) GPL-2.0 PHPViews3viewsFree
ErgoCommunicationModern IRCv3 server written in Go, combining the features of an ircd, a services framework, and a bouncer. ([Source Code](https://github.com/ergochat/ergo)) MIT Go/DockerViews3viewsFree
InspIRCdCommunicationModular IRC server written in C++ for Linux, BSD, Windows, and macOS. ([Source Code](https://github.com/inspircd/inspircd)) GPL-2.0 C++/DockerViews3viewsFree
Kiwi IRCCommunicationResponsive web IRC client with theming support. ([Demo](https://kiwiirc.com/nextclient/), [Source Code](https://github.com/kiwiirc/kiwiirc)) Apache-2.0 NodejsViews3viewsFree
ntfyCommunicationPush 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/binwiederhViews3viewsFree
SAMACommunicationNext-Gen self-hosted chat server and clients. ([Demo](https://app.samacloud.io/demo), [Source Code](https://github.com/SAMA-Communications/sama-server), [Clients](https://github.com/SAMA-CommunicationViews3viewsFree
TiledeskCommunicationAll-in-one customer engagement platform from lead-gen to post-sales, from WhatsApp to your website. With omni-channel live agents and AI-powered chatbots (alternative to Intercom, Zendesk, Tawk.to andViews3viewsFree
Maddy Mail ServerCommunicationAll-in-one mail server that implements SMTP (both MTA and MX) and IMAP. Replaces Postfix, Dovecot, OpenDKIM, OpenSPF, OpenDMARC with single daemon. ([Source Code](https://github.com/foxcpp/maddy)) GPLViews3viewsFree
MoxCommunicationComplete e-mail solution with IMAP4, SMTP, SPF, DKIM, DMARC, MTA-STS, DANE and DNSSEC, reputation-based and content-based junk filtering, Internationalization (IDNA), automatic TLS with ACME and Let'sViews3viewsFree
RoundcubeCommunicationBrowser-based IMAP client with an application-like user interface. ([Source Code](https://github.com/roundcube/roundcubemail)) GPL-3.0 PHP/debViews3viewsFree
SIP3CommunicationVoIP troubleshooting and monitoring platform. ([Demo](https://demo.sip3.io), [Source Code](https://github.com/sip3io/)) Apache-2.0 JavaViews3viewsFree
SIPCAPTURE HomerCommunicationTroubleshooting and monitoring VoIP calls. ([Source Code](https://github.com/sipcapture/homer)) AGPL-3.0 Nodejs/Go/DockerViews3viewsFree
MisskeyCommunicationDecentralized app-like microblogging server/SNS for the Fediverse, using the ActivityPub protocol like GNU social and Mastodon. ([Source Code](https://github.com/misskey-dev/misskey)) AGPL-3.0 Nodejs/Views3viewsFree
OSSNCommunicationSocial networking software that allows you to make a social networking website and helps your members build social relationships, with people who share similar professional or personal interests. ([SoViews3viewsFree
ejabberdCommunicationXMPP instant messaging server. ([Source Code](https://github.com/processone/ejabberd)) GPL-2.0 Erlang/DockerViews3viewsFree
OpenRouteServiceCommunicationRoute service with directions, isochrones, time-distance matrix, route optimization, etc. ([Demo](https://openrouteservice.org/dev/#/api-docs/introduction), [Source Code](https://github.com/GIScience/Views3viewsFree
OwncastCommunicationDecentralized single-user live video streaming and chat server for running your own live streams similar in style to the large mainstream options. ([Source Code](https://github.com/owncast/owncast)) MViews3viewsFree
ReadAnyCommunicationAI-powered e-book reader with semantic search, chat, and note management. [![Open-Source Software][OSS Icon]](https://github.com/codedogQBY/ReadAny) ![Freeware][Freeware Icon]Views3viewsFree
JanCommunicationAn open-source alternative to ChatGPT that runs entirely offline on your computer. [![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]](https://github.com/menloresearch/jan)Views3viewsFree
FerdiumCommunicationMessaging workspace that combines multiple web apps in one place. [![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]](https://github.com/ferdium/ferdium-app)Views3viewsFree
KeybaseCommunicationSecure groups, files, and chat for everyone! [![Open-Source Software][OSS Icon]](https://github.com/keybase) ![Freeware][Freeware Icon]Views3viewsFree
MastodonCommunicationYour self-hosted, globally interconnected microblogging community [![Freeware][Freeware Icon]](https://joinmastodon.org/apps) [![Open-Source Software][OSS Icon]](https://github.com/mastodon/mastodon)Views3viewsFree
TelegramCommunicationMessaging app with a focus on speed and security. [![Open-Source Software][OSS Icon]](https://github.com/overtake/TelegramSwift) [![App Store][app-store Icon]](https://apps.apple.com/us/app/telegram/iViews3viewsFree
Audio HijackCommunicationRecord any application's audio, including VoIP calls from Skype, web streams from Safari, and much more.Views3viewsFree
ChatboxCommunicationUser-friendly Desktop Client App for AI Models/LLMs (GPT, Claude, Gemini, Ollama...). [![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]](https://github.com/chatboxai/chatbox)Views3viewsFree
MacaifyCommunicationFast use of ChatGPT, lightweight, clean, keyboard-first. ![Freeware][Freeware Icon]Views3viewsFree
MattermostCommunicationa flexible, open-source messaging platform that meets even the most demanding privacy and security standards. , based on GTK+. ([Source Code](https://git.claws-mail.org/?p=claws.git;a=tree)) GPL-3.0 CViews3viewsFree
OpenTrashmailCommunicationComplete trashmail solution that exposes an SMTP server and has a web interface to manage received emails. Works with multiple and wildcard domains and is fully file based (no database needed). IncludGH862GitHub starsViews3viewsOpen Source
clevercliCommunicationCollection of ChatGPT powered utilities.GH165GitHub starsViews3viewsOpen Source
ErrbotCommunicationPlugin based chatbot designed to be easily deployable, extensible and maintainable. ([Source Code](https://github.com/errbotio/errbot)) GPL-3.0 PythonViews3viewsFree
JitsiCommunicationmulti-platform open-source video conferencing you can install yourself or use on their servers.  ) NLPL PerlViews3viewsFree
MuttCommunicationSmall but very powerful text-based mail client. ([Source Code](https://gitlab.com/muttmua/mutt)) GPL-2.0 CViews3viewsFree
SylpheedCommunicationStill developed predecessor to Claws Mail, lightweight mail client. ([Source Code](https://github.com/sylpheed-mail/sylpheed)) GPL-2.0 CViews3viewsFree
TauCommunicationEasily build Cloud Computing Platforms with features like Serverless WebAssembly Functions, Frontend Hosting, CI/CD, Object Storage, K/V Database, and Pub-Sub Messaging. ([Source Code](https://github.Views3viewsFree
PleromaCommunicationFederated microblogging server, Mastodon, GNU social, & ActivityPub compatible. ([Source Code](https://git.pleroma.social/pleroma/pleroma)) AGPL-3.0 ElixirViews3viewsFree
MailCatcherCommunicationRuby gem that deploys a simply SMTP MTA gateway that accepts all mail and displays in web interface. Useful for debugging or development.Views3viewsFree
docker-mailserverCommunicationProduction-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. Only configuration files, no SQL database. ([Source Code](https://github.comViews3viewsFree
AWStatsCommunicationGenerate statistics from web, streaming, ftp or mail server logfiles. ([Demo](https://www.awstats.org/#DEMO), [Source Code](https://github.com/eldy/awstats)) GPL-3.0 PerlViews3viewsFree
MumbleCommunicationLow-latency, high quality voice/text chat software. ([Source Code](https://github.com/mumble-voip/mumble), [Clients](https://wiki.mumble.info/wiki/3rd_Party_Applications)) BSD-3-Clause C++/debViews3viewsFree
TuwunelCommunicationHigh-performance and feature-rich chat server for Matrix, and the successor to conduwuit (fork of Conduit). ([Demo](https://try.tuwunel.chat/), [Source Code](https://github.com/matrix-construct/tuwuneViews3viewsFree
The LoungeCommunicationSelf-hosted web IRC client. ([Demo](https://demo.thelounge.chat/), [Source Code](https://github.com/thelounge/thelounge)) MIT Nodejs/DockerViews3viewsFree
NoosferoCommunicationPlatform for social and solidarity economy networks with blog, e-Portfolios, CMS, RSS, thematic discussion, events agenda and collective intelligence for solidarity economy in the same system. AGPL-3.Views3viewsFree
Jitsi Video BridgeCommunicationWebRTC compatible Selective Forwarding Unit (SFU) that allows for multiuser video communication. ([Source Code](https://github.com/jitsi/jitsi-videobridge)) Apache-2.0 Java/debViews3viewsFree
CitadelCommunicationGroupware including email, calendar/scheduling, address books, forums, mailing lists, IM, wiki and blog engines, RSS aggregation and more. ([Source Code](https://www.citadel.org/source.html)) GPL-3.0 Views3viewsFree
remioCommunicationLocal-first AI chat client that answers from your knowledge base. [![Freeware][Freeware Icon]](https://www.remio.ai/?utm_source=github_list)Views3viewsFree
chasquidCommunicationSMTP (email) server with a focus on simplicity, security, and ease of operation. ([Source Code](https://blitiri.com.ar/git/r/chasquid/)) Apache-2.0 GoViews3viewsFree
ContinuwuityCommunicationCommunity-driven Matrix homeserver, the continuation of conduwuit focusing on user experience and new features (fork of Conduit). ([Source Code](https://forgejo.ellis.link/continuwuation/continuwuity)Views3viewsFree
DittofeedCommunicationOmni-channel customer engagement and messaging automation platform (alternative to Braze, Customer.io, Iterable). ([Demo](https://demo.dittofeed.com/dashboard/journeys), [Source Code](https://github.cViews3viewsFree
DatabagCommunicationFederated, end-to-end encrypted messaging service for the web, iOS, and Android, supporting text, photos, video, and WebRTC video and audio calls. ([Demo](https://databag.coredb.org/#/create)) Apache-GH1.5KGitHub starsViews3viewsOpen Source
SnappyMailCommunicationSimple, modern, lightweight & fast web-based email client (fork of RainLoop). ([Demo](https://snappymail.eu/demo/), [Source Code](https://github.com/the-djmaze/snappymail), [Clients](https://snappymaiViews3viewsFree
GoToSocialCommunicationActivityPub federated social network server implementing the Mastodon client API. ([Source Code](https://codeberg.org/superseriousbusiness/gotosocial)) AGPL-3.0 Docker/GoViews3viewsFree
HatsuCommunicationBridge that interacts with Fediverse on behalf of your static site. ([Source Code](https://github.com/importantimport/hatsu)) AGPL-3.0 Docker/RustViews3viewsFree
MiroTalk SFUCommunicationSimple, secure, scalable real-time video conferences up to 4k, compatible with all browsers and platforms. ([Demo](https://sfu.mirotalk.com/newroom), [Source Code](https://github.com/miroslavpejic85/mViews3viewsFree
GotifyCommunicationNotification server with Android and CLI clients (alternative to PushBullet). ([Source Code](https://github.com/gotify/server), [Clients](https://github.com/gotify/android)) MIT Go/DockerViews3viewsFree
DiscourseCommunicationAdvanced forum / community solution based on Ruby and JS. ([Demo](https://try.discourse.org/), [Source Code](https://github.com/discourse/discourse)) GPL-2.0 DockerViews3viewsFree
PostalCommunicationComplete and fully featured mail server for use by websites & web servers. ([Source Code](https://github.com/postalserver/postal)) MIT Docker/RubyViews3viewsFree
LangfuseCommunicationLLM engineering platform for model tracing, prompt management, and application evaluation. Langfuse helps teams collaboratively debug, analyze, and iterate on their LLM applications such as chatbots oViews3viewsFree
CastopodCommunicationPodcast management hosting platform that includes the latest podcast 2.0 standards, an automated Fediverse feed, analytics, an embeddable player, and more. ([Source Code](https://code.castopod.org/adaViews3viewsFree
RamboxCommunicationMessaging and emailing app that combines common web applications into one. [![Open-Source Software][OSS Icon]](https://github.com/saenzramiro/rambox) ![Freeware][Freeware Icon]Views3viewsFree
MisskeyCommunication🌎 A completely free and open interplanetary microblogging platform 🚀 [![Open-Source Software][OSS Icon]](https://github.com/misskey-dev/misskey)Views3viewsFree
HomeServerHQCommunicationAll-in-one home server infrastructure and installer. Have a fully configured email server, VPN, and public website(s) set up in less than an hour, even behind CGNAT. ([Source Code](https://github.com/Views3viewsFree
PPomoPlan — Pomodoro, Tasks & HabitsCommunicationPomodoro, to do list & habit tracker with Eisenhower MatrixViews3viewsFreemium
Robust IRCCommunicationIRC without netsplits. Distributed IRC server, based on RobustSession protocol. ([Source Code](https://github.com/robustirc/robustirc)) BSD-3-Clause GoViews3viewsFree
WeechatCommunicationFast, light and extensible chat client. ([Source Code](https://github.com/weechat/weechat)) GPL-3.0 C/Docker/debViews3viewsFree
AsteriskCommunicationEasy to use but advanced IP PBX system, VoIP gateway and conference server. ([Source Code](https://github.com/asterisk/asterisk)) GPL-2.0 C/debViews3viewsFree
AkkomaCommunicationFederated microblogging server with Mastodon, GNU social, and ActivityPub compatibility. ([Source Code](https://akkoma.dev/AkkomaGang/akkoma)) AGPL-3.0 Elixir/DockerViews3viewsFree
diaspora*CommunicationDistributed social networking server. ([Source Code](https://github.com/diaspora/diaspora)) AGPL-3.0 RubyViews3viewsFree
HumHubCommunicationFlexible kit for private social networks. ([Source Code](https://github.com/humhub/humhub)) AGPL-3.0 PHPViews3viewsFree
Iceshrimp.NETCommunicationFederated microblogging server that communicates over ActivityPub. ([Source Code](https://iceshrimp.dev/iceshrimp/iceshrimp.net)) EUPL-1.2 .NET/C#/DockerViews3viewsFree
IssoCommunicationLightweight commenting server written in Python and Javascript. It aims to be a drop-in replacement for Disqus. ([Source Code](https://github.com/isso-comments/isso)) MIT Python/DockerViews3viewsFree
LemmyCommunicationLink aggregator for the fediverse (alternative to Reddit). ([Source Code](https://github.com/LemmyNet/lemmy)) AGPL-3.0 Docker/RustViews3viewsFree
MisagoCommunicationFully featured modern forum application that is fast, scalable and responsive. ([Source Code](https://github.com/rafalp/Misago)) GPL-2.0 DockerViews3viewsFree
MovimCommunicationModern, federated social network based on XMPP, with a fully featured group-chat, subscriptions and microblogging. ([Source Code](https://github.com/movim/movim)) AGPL-3.0 PHP/DockerViews3viewsFree
NodeBBCommunicationForum software built for the modern web. ([Demo](https://try.nodebb.org/), [Source Code](https://github.com/NodeBB/NodeBB)) GPL-3.0 Nodejs/DockerViews3viewsFree
phpBBCommunicationFlat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website. ([Source Code](https://github.com/phpbb/phpbb)) GPL-2.0 PHPViews3viewsFree
remark42CommunicationLightweight and simple comment engine, which doesn't spy on users. It can be embedded into blogs, articles or any other place where readers add comments. ([Demo](https://remark42.com/demo/), [Source CViews3viewsFree
BigBlueButtonCommunicationSupports real-time sharing of audio, video, slides (with whiteboard controls), chat, and the screen. Instructors can engage remote students with polling, emojis, and breakout rooms. ([Source Code](httViews3viewsFree
GaleneCommunicationVideo conferencing server that is easy to deploy and that requires moderate server resources. ([Source Code](https://github.com/jech/galene)) MIT GoViews3viewsFree
Jitsi MeetCommunicationWebRTC application that uses Jitsi Videobridge to provide high quality, scalable video conferences. ([Demo](https://meet.jit.si), [Source Code](https://github.com/jitsi/jitsi-meet)) Apache-2.0 Nodejs/Views3viewsFree
MiroTalk C2CCommunicationReal-time cam-2-cam video calls & screen sharing, end-to-end encrypted, to embed in any website with a simple iframe. ([Source Code](https://github.com/miroslavpejic85/mirotalkc2c)) AGPL-3.0 Nodejs/DoViews3viewsFree
MiroTalk P2PCommunicationSimple, secure, fast real-time video conferences up to 4k and 60fps, compatible with all browsers and platforms. ([Demo](https://p2p.mirotalk.com/newcall), [Source Code](https://github.com/miroslavpejViews3viewsFree
MongooseIMCommunicationMobile messaging platform with a focus on performance and scalability. ([Source Code](https://github.com/esl/MongooseIM)) GPL-2.0 Erlang/Docker/K8SViews3viewsFree
TigaseCommunicationXMPP server implementation in Java. ([Source Code](https://github.com/tigase/tigase-server)) GPL-3.0 JavaViews3viewsFree
Converse.jsCommunicationXMPP chat client in your browser. ([Source Code](https://github.com/conversejs/converse.js)) MPL-2.0 JavascriptViews3viewsFree
PeergosCommunicationSecure and private space online where you can store, share and view your photos, videos, music and documents. Also includes a calendar, news feed, task lists, chat and email client. ([Source Code](httViews3viewsFree
ColanodeCommunicationCollaboration suite with real-time messaging, rich text pages, file management, and dynamic databases - built for offline work (alternative to Slack, Notion). ([Source Code](https://github.com/colanodViews3viewsFree
OpenmeetingsCommunicationVideo conferencing, instant messaging, whiteboard, collaborative document editing and other groupware tools using API functions of the Red5 Streaming Server for Remoting and Streaming. ([Source Code](Views3viewsFree
SOGoCommunicationSOGo offers multiple ways to access the calendaring and messaging data. CalDAV, CardDAV, GroupDAV, as well as ActiveSync, including native Outlook compatibility and Web interface. ([Demo](https://demoViews3viewsFree
PrivateBinCommunicationMinimalist pastebin/discussion board where the server has zero knowledge of hosted data. ([Demo](https://privatebin.net/), [Source Code](https://github.com/PrivateBin/PrivateBin)) Zlib PHPViews3viewsFree
MobilizonCommunicationFederated tool that helps you find, create and organise events and groups. ([Source Code](https://framagit.org/framasoft/mobilizon/)) AGPL-3.0 Elixir/DockerViews3viewsFree
SyncloudCommunicationYour own online file storage, social network or email server. ([Source Code](https://github.com/syncloud/platform)) GPL-3.0 Go/ShellViews3viewsFree
PagureCommunicationLightweight, powerful, and flexible git-centric forge with features laying the foundation for federated and decentralized development. ([Demo](https://pagure.io/)) GPL-2.0 Docker/Python/debViews3viewsFree
GitterCommunicationChat platform for developers and GitHub communities. ![Freeware][Freeware Icon]Views3viewsFree
FranzCommunicationMessaging app that combines multiple chat services in one place. ![Freeware][Freeware Icon]Views3viewsFree
LarkCommunicationThe Next-Gen Collaboration Suite. All your chats, meetings, calendars, docs, and emails in one place. ![Freeware][Freeware Icon]Views3viewsFree
LimeChatCommunicationOpen-source IRC client for Mac OS X. [![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]](https://github.com/psychs/limechat)Views3viewsFree
MattermostCommunicationOpen-source team collaboration platform. [![Open-Source Software][OSS Icon]](https://github.com/mattermost/mattermost) ![Freeware][Freeware Icon]Views3viewsFree
PostboxCommunicationPowerful, simple and beautiful email client, need to pay for a license.Views3viewsFree
WeChatCommunicationOfficial WeChat app for Mac. ![Freeware][Freeware Icon] ![App Store][app-store Icon]Views3viewsFree
MailspringCommunicationA beautiful, fast, and fully open source mail client. [![Open-Source Software][OSS Icon]](https://github.com/Foundry376/Mailspring) ![Freeware][Freeware Icon]Views3viewsFree
Lens StudioCommunicationcreate, publish, and share your own AR experiences for Snapchat with or without code. Views3viewsFree
FlexisipCommunicationComplete, modular and scalable SIP server, includes a push gateway, to deliver SIP incoming calls or text messages on mobile device platforms where push notifications are required to receive informatiViews3viewsFree
cpp-linter-actionCommunicationA Github Action for linting C/C++ code integrating clang-tidy and clang-format to collect feedback provided in the form of thread comments and/or annotations.Views3viewsFree
EggdropCommunicationThe world's most popular Open Source IRC bot, designed for flexibility and ease of use.Views3viewsFree
ErrCommunicationA plugin based chatbot designed to be easily deployable, extensible and maintainable.Views3viewsFree
MaildropCommunicationOpen Source disposable email SMTP server, also useful for development.GH725GitHub starsViews3viewsOpen Source
DevOpsLinksCommunicationA community of DevOps, SysAdmin & Developers with a weekly newsletter and a team chat.Views3viewsFree
ngircdCommunicationPortable and lightweight Internet Relay Chat server for small or private networks. ([Source Code](https://github.com/ngircd/ngircd)) GPL-2.0 C/debViews2viewsFree
BoltAICommunicationA beautiful & powerful ChatGPT app for Mac. Stay ahead by integrating AI into your workflow today.Views2viewsFree
UnrealIRCdCommunicationModular, advanced and highly configurable IRC server written in C for Linux, BSD, Windows, and macOS. ([Source Code](https://github.com/unrealircd/unrealircd)) GPL-2.0 CViews2viewsFree
CortezaCommunicationCRM including a unified workspace, enterprise messaging and a low code environment for rapidly and securely delivering records-based management solutions. ([Demo](https://latest.cortezaproject.org), [Views2viewsFree
ZNCCommunicationAdvanced IRC bouncer. ([Source Code](https://github.com/znc/znc)) Apache-2.0 C++/debViews2viewsFree
PolymailCommunicationSimple, beautiful and powerful email client. ![Freeware][Freeware Icon]Views2viewsFree
ZulipCommunicationZulip is a powerful, open source group chat application. ([Source Code](https://github.com/zulip/zulip)) Apache-2.0 PythonViews2viewsFree
ArtalkCommunicationComment system built in Golang, providing a lightweight and highly customizable solution for adding comments to your website. ([Source Code](https://github.com/ArtalkJS/Artalk)) MIT Go/DockerViews2viewsFree
wildduckCommunicationScalable no-SPOF IMAP/POP3 mail server. ([Source Code](https://github.com/zone-eu/wildduck)) EUPL-1.2 Nodejs/DockerViews2viewsFree
TeambitionCommunicationTeam collaboration tool for tasks, schedules, files, and discussions. ![Freeware][Freeware Icon]Views2viewsFree
AdiumCommunicationFree instant messaging application for Mac OS X. Connect to AIM, MSN, SMPP, Yahoo and more. ![Freeware][Freeware Icon]Views2viewsFree
DingTalkCommunicationTeam communication and collaboration platform. ![Freeware][Freeware Icon]Views2viewsFree
HarakaCommunicationFast, highly extensible, and event driven SMTP server. ([Source Code](https://github.com/haraka/Haraka)) MIT NodejsViews2viewsFree
MastodonCommunicationFederated microblogging server. ([Source Code](https://github.com/mastodon/mastodon), [Clients](https://github.com/hyperupcall/awesome-mastodon)) AGPL-3.0 RubyViews2viewsFree
FlarumCommunicationDelightfully simple forums. Flarum is the next-generation forum software that makes online discussion fun again. ([Source Code](https://github.com/flarum/flarum)) MIT PHPViews2viewsFree
ZimbraCommunicationCollaborative software suite, that includes an email server and web client.Views2viewsFree
MyBBCommunicationFree, extensible forum software package. ([Source Code](https://github.com/mybb/mybb)) LGPL-3.0 PHPViews2viewsFree
WriteFreelyCommunicationWriting software for starting a minimalist, federated blog — or an entire community. ([Source Code](https://github.com/writefreely/writefreely)) AGPL-3.0 GoViews2viewsFree
Edison MailCommunicationA customisable, simple, and beautiful email client. ![Freeware][Freeware Icon]Views2viewsFree
CloudBotCommunicationThe simple, fast, expandable, open-source Python IRC bot.GH290GitHub starsViews2viewsOpen Source
CentrifugoCommunicationLanguage-agnostic real-time messaging (Websocket or SockJS) server. ([Demo](https://github.com/centrifugal/centrifugo#demo), [Source Code](https://github.com/centrifugal/centrifugo)) MIT Go/Docker/K8SViews2viewsFree
GGPT‑5.5 InstantCommunicationSmarter, more personal answers as ChatGPT's new defaultViews2viewsFreemium
TabbitCommunicationAn AI-native browser that understands your context, chats with webpages, and automates tasks. ![Freeware][Freeware Icon]Views2viewsFree
Spectrum 2CommunicationSpectrum 2 is an open source instant messaging transport. It allows users to chat together even when they are using different IM networks. ([Source Code](https://github.com/SpectrumIM/spectrum2)) GPLViews2viewsFree
CyTubeCommunicationSynchronize media, chat, and more for an arbitrary number of channels. ([Demo](https://cytu.be)) MIT NodejsGH1.6KGitHub starsViews2viewsOpen Source
Prosody IMCommunicationFeature-rich and easy to configure XMPP server. ([Source Code](https://hg.prosody.im/)) MIT LuaViews2viewsFree
SnikketCommunicationAll-in-one Dockerized easy XMPP solution, including web admin and clients. ([Source Code](https://github.com/snikket-im/snikket-server), [Clients](https://snikket.org/app/)) Apache-2.0 DockerViews2viewsFree
ChitchatterCommunicationPeer-to-peer chat app that is serverless, decentralized, and ephemeral. ([Source Code](https://github.com/jeremyckahn/chitchatter)) GPL-2.0 NodejsViews2viewsFree
aye-chatCommunicationWorkspace for editing, running commands, and chatting with your codebase.GH64GitHub starsViews2viewsOpen Source
ZulipCommunicationcombines the immediacy of real-time chat with an email threading model, helping to focus on important conversations while ignoring irrelevant ones. ) GPL-2.0 PHPViews2viewsFree
SocialhomeCommunicationFederated and decentralized profile builder and social network engine. ([Demo](https://socialhome.network/), [Source Code](https://github.com/jaywink/socialhome)) AGPL-3.0 Docker/PythonViews2viewsFree
Onyx Community EditionCommunicationChat UI that works with any LLM. It comes loaded with advanced features like agents, web search, RAG, MCP, deep research, Connectors to 40+ knowledge sources, and more. ([Source Code](https://github.cViews2viewsFree