• Slacking Off

last modified May 3 by strypey

When commons stewardship organisations like CreativeCommons (and open source projects) started to use it in place of IRC, Slack was justified on the basis that people didn't have to use the proprietary (and awful) Slack client. Instead they could use their choice of IRC or XMPP client. That allowed Slack to enclose organisations that otherwise never have gone there, and now that IRC and XMPP has been removed from Slack, they're locked in, because Slack has their chat history. A classic bait-and-switch tactic. This page is about free code software your team could use in place of Slack. Apps within each section are listed in alphabetical order.

A few questions to help you decide what to replace Slack with:

  • do you use Slack mainly to communicate with a team, or as more of a chat-based social network?
  • are you in a position to self-host a team chat package, or are you only interested in using hosted services?
  • do you use Slack mainly for realtime chat, or asynchronous messages, or equally for both?
  • is voice and video mission critical, or do you only need text chat?
  • how important is your chat history? Is it an essential archive of your institutional memory, like mailing list archives? Is it ephemeral, like idling in IRC, with your team usually summarizing Slack chat in docs on a wiki or whatever?
  • do you want it to allow federation between different servers, or are you happy having all participants set up an account on one server (yours or a third-party host) with backups?
  • is email integration of interest, or are you all drowning in email and not wanting email delivery/ replies as a option? (I'm guessing it's not that important since Slack has no email bridge, but...)

Chat-like Slack replacements

Key criteria for being included here as a possible Slack replacement is supporting realtime text chat, and having at least one way of using it in on the web, so its usable by anyone with a web browser. But like Slack itself, many of these projects can also be used via desktop and mobile apps. Also, some of these projects may integrate with voice/ video chat systems (see Core-Us ).


If what you're look for is a private chat space for your team, or your organization, rather than a chat-based social network, one of these is probably your best option:

  • Let's Chat ("MIT"): Demo available by clicking 'Try a Demo' on the home page, or at Bitnami. Compatible with XMPP/ MUC (see below), so a Let's Chat server can be accessed from any XMPP client, but the interface and features are so Slack-a-like I decided to put it in this category.


If a chat-based social network is what you're looking for, where you can easily connect with other people involved in free code development and other commons projects, one of these could be for you:

  • The fediverse: not an app or a service, but rather a federation of services (or "instances") each running one of a range of apps (eg GNU social, Mastodon) that can federate with each other. Each app uses one or more of the shared standards/ protocols for social networking on the web, the most popular being ActivityPub. The original fediverse apps were desiged more as a micro-blogging network, but can be used for team discussions using Direct Messages, and particularly for discussion between teams around solving shared problems.
  • Gitter ("MIT"): The hosted instance at Gitter.im is run by GitLab and free to use. 'Slack ... has limitations for large communities and public usage. All of Gitter’s public conversation history is completely unlimited, open, archived and indexed by popular search engines, contributing the public knowledge base of the internet." - GitLab announcement about buying Gitter.
  • Kontalk (various licenses): "Kontalk is run by a community of volunteers offering servers and splitting costs among them", all software used in both the XMPP servers and clients they distribute is free code. Full end-to-end encryption for both client-to-server and server-to-server channels.


The eXtensible Messaging and Presence Protocol was originally designed to for one-to-one Instant Messaging (IM), basically a way to see if a friend or coworker is online and available to chat, and send short text message back and forth in realtime. It can also support chat rooms using Multi-User Chat (MUC), like an Internet Relay Chat (IRC) channel, but unlike IRC, you don't have to be on the XMPP server hosting the chat room to participate. Slack's stated mission is to provide team communications, not casual watercooler chat, and rose to its current popularity due to a perceived lack of team-specific features and user-friendliness in XMPP and IRC software. That said, if your team only started using Slack because "everyone is there", and you're comfortable with choosing an XMPP app with Slack-a-like features that may not work with all other XMPP servers and clients, these web-based apps may be of interest:

  • inVerse (MPL 2.0): A fullscreen version of Converse.JS.
  • JSXC ("MIT"): web client for XMPP. Was (is?) used by Diaspora to provide a realtime chat feature.
  • Libervia (AGPLv3): Web client for Salut à Toi (AGPLv3). An experiment with building a federated blogging and forum network app on XMPP.
  • Movim (AGPLv3): An experiment with building a federated social network app on XMPP.
  • Xabber (AGPLv3): Aim to support all the new features added in recent extensions to XMPP. Native app for Android also available.


Forum-like Slack Replacements

Maybe you found yourself using Slack because you needed a comms tool that has a better set of team features than most email lists, but you actually find realtime chat distracting rather than useful. Key criteria for being included here as a possible Slack replacement is supporting asynchronous text chat, and having at least one way of using it in on the web, so its usable by anyone with a web browser. But like Slack itself, many of these projects can also be used via desktop and mobile apps.


Possible Alternatives to Slack-a-likes

These are text chat tools that don't have a web app. To even test them, you need to download a desktop or mobile app (whichever is available). They are included here for anyone who wants the total opposite of Slack.

  • Patchwork (AGPLv3): a P2P social network that federates with the SSB (Secure Scuttlebutt) protocol. Desktop apps are available for GNU/Linux, Mac, and Windows. There is also an Android/Linux app for SSB called Manyverse (MPLv2).



Free code Slack-a-likes that seem to have been started and then abandoned. Included here for completeness, and in case studying the code may help someone:

  • Candy ("MIT"): web client for XMPP, the only one I'm aware of to add WebRTC support. Was handed over to the Adhearsion Foundation before development ceased.

Sources: mainly blog pieces pointing out the problems with Slack for open source communities, and suggesting replacements:

  • 2015: 'Self-Hosted Team Chat Options and Alternatives' - Andrei Soroker and Niral Patel, SameRoom blog
  • 2015: 'Please don't use Slack for FOSS projects' - Drew DeVault's blog
  • 2015: 'So Yeah We Tried Slack… and We Deeply Regretted It' - FreeCodeCamp blog
  • 2016: 'Software Slack smackback: There's no IRC in team (software), say open-sourcers' - Scott Gilbertson, The Register 
  • 2017: 'Goodbye Slack and hello open-source messaging platform' - Wilhelm, Santiment blog
  • 2017: 'Why Slack is inappropriate for open source communications' - Dave Cheney's blog 
  • 2017: '5 open source alternatives to Slack for team chat' - Jason Baker, OpenSource.com
  • 2018: 'Why Slack is better, and why open communities shouldn't use it' - Dave Lane's blog


  •  Could add ChatSecure/ Tor Messenger / Zom, and maybe a whole new category for P2P/ distributed chat tools like Scuttlebutt, Tox, Ring, Briar, and Serval Mesh?
  • Need to put together a table of potential replacements, covering criteria like; free code, federated, protocol support, voice, video etc. Maybe something exists on Wikipedia or P2P Foundation wiki that I could adapt and contribute to? Maybe I could create a table on one of those wikis?