Mattermost 2.0: Open Source, Slack-compatible localized messaging alternative


We’re a YC-backed open source company releasing a self-hosted, localizable Slack-alternative: Mattermost 2.0.

You can download, install and run Mattermost for free as open source software at

Just like Slack, teams can share messages and files across PC and phones with continuous archiving, instant search, and dozens of 3rd party integrations.

Mattermost mobile experience with comment threads and file sharing

Unlike Slack:

1. Mattermost supports multiple languages

Mattermost 2.0 includes Spanish. French, Dutch and Brazilian Portuguese projects are underway. Users can customize translations and even self-localize team sites.

2. Mattermost is self-hosted

Your communications are never stored on someone else’s computer. Keep your promise to customers, patients, and consumers that their private data is never shared.

3. Mattermost is open

You have complete transparency, complete access and complete control. Mattermost is open source software for teams, with new releases available monthly under an MIT license.

Slack-compatible, not Slack-limited

We’re building an open alternative to proprietary SaaS products by being “Slack-compatible, not Slack-limited”.

The first step was Mattermost matching Slack’s core features:

  • Sharing messages and files in public, private and direct message channels
  • Viewing video, audio, images and animated files
  • Customizing notifications on mentions of names and keywords
  • Searching and filtering by channel, user and keywords
  • Access from PC and native mobile apps
  • Full markdown support in messages, including tables and embedded images
  • Slack-compatible webhooks, slash commands and integrations

Mattermost messaging, file sharing and search

The next step was going beyond Slack’s limitations, first in small ways:

  • Label and search by hashtags (Slack doesn’t offer hashtags)
  • Comments on any message (Slack limits comments to files only)
  • 20-option color themes (Slack limits themes to 8 color options)
  • 4 custom code themes (Slack doesn’t offer code themes)
  • 11 font options (Slack removed font options, only 1 choice now)

Then in larger ones:

Multi-language Support

Less than 6% of the world speak English as a native language. English is only the 3rd most popular language after Mandarin and Spanish. We believe to become an effective communications platform, multi-language support is a critical feature.

Mattermost 2.0 offers Spanish language translation

Immense thanks to Elias Nahum who spent months preparing for his twelve thousand line pull request to add localization and Spanish-language translation to Mattermost 2.0.

Data Center Readiness

Mattermost is built to run behind your firewall. It installs as a compiled binary with step-by-step install guides for Ubuntu, Debian, and RHEL/Oracle/CentOS. It upgrades easily and has a host of community installers for Docker, Puppet, CloudFoundry, Heroku and Jelastic.

If you have a Mac, you can get Mattermost up and running locally in one line using Docker. or consult our deployment guide to see how Mattermost would slot into your data center.

Check out extensive documentation available on

Mattermost deployment overview

View full image

Open Community

What makes Mattermost special is its worldwide community of contributors and users that are constantly improving the product.

As a partial list, in the last 4 months the community has created Mattermost integration with IRC, XMPP, Jira, Trac, Redmine, KanBoard, Nagios, Sentry, Jenkins, Rundeck, PowerShell, Mercurial, Subversion, GitLab, Twitter, RSS, Bugzilla, Gerrit, Email lists, Disqus, Node, Threema, and Hubot.

The community momentum has been incredible, and we’re thrilled to be named a “Top 10 Open Source Project for 2015” by

Mattermost named a Top 10 Open Source Project of 2015 by

In addition to the developers of Mattermost integrations and installers, we want to say a huge THANK YOU to all the contributors for Mattermost 2.0: enahum, trashcan, alanmoo, fallenby, loafoe, gramakri, pawelad, cifvts, rosskusler, apskim, and khoa-le.

Coming Soon

  • Updated Mattermost iOS app v2.0.0 supporting GitLab single-sign-on and (for Enterprise Edition servers) Active Directory and LDAP single-sign-on soon available in iTunes. Requires Mattermost server v2.0 and later.
  • New Mattermost Android app to be open sourced by end of February.
  • The commercial version of Mattermost built for enterprises is nearing beta. To request access to the pre-released version with Active Directory and LDAP single-sign-on and other features contact the Enterprise Team.

Lindsay Brock is the former Head of Product for Mattermost, Inc. Prior to joining Mattermost in January 2015, she served as a product manager for SpinPunch, a Y Combinator-backed online gaming startup. Lindsay is an alumnus of the University of Waterloo, where she earned a bachelor of applied science degree in engineering.