Mattermost is an open source, on-prem Slack-alternative

Mattermost modernizes team communication without locking in your data to a single provider.

Offer your end users messaging and file sharing across PCs and phones with archiving and instant search--without losing control of your data.

All team communication in one place, searchable and accessible anywhere

Please see the features pages of the Mattermost website for images and further description of the functionality listed below:

Sharing Messaging and Files

• Send messages, comments, files and images across public, private and 1-1 channels
• Personalize notifications for unreads and mentions by channel and keyword
• Use #hashtags to tag and find messages, discussions and files

Archiving and Search

• Import Slack user accounts and channel archives
• Search public and private channels for historical messages and comments
• View recent mentions of your name, username, nickname, and custom search terms

Anywhere Access

• Use Mattermost from web-enabled PCs and phones
• Attach sound, video and image files from mobile devices
• Define team-specific branding and color themes across your devices

Enterprise Compatible

• Self-host Mattermost entirely within your organization's insfrastructure
• GitLab Mattermost omnibus supports install to over 100,000 organizations using GitLab
• LDAP/Active Directory connectivity to Mattermost enabled via GitLab Single-Sign-On

Learn More

• Product Vision and Target Audiences - What we're solving and for whom are we building
• Mattermost Forum - For technical questions and answers
• Issue Tracker - For reporting bugs
• Feature Ideas Forum - For sharing ideas for future versions
• Contributuion Guidelines - For contributing code or feedback to the project

Follow us on Twitter at @MattermostHQ.

Installing Mattermost

There are multiple ways to install Mattermost depending on your needs.

Quick Start Install for Product Evaluation

• Local Machine Install and Upgrade with Docker - Explore product functionality using a single-container Docker install on a local machine, including Mac OSX, Ubuntu, or Arch Linux). Optionally set up email and upgrade your instance using DockerHub.

• AWS EBS Install and Upgrade with Docker - Explore product functionality using a single-container Docker install for Amazon Web Services Elastic Beanstalk. Optionally set up email and upgrade your instance using DockerHub.

Development Install

• Developer Machine Setup - Setup your local machine development environment using Docker on Mac OSX or Ubuntu.

Production Deployment (for Beta2 and later)

Prior to production installation, please review Mattermost system requirements.

• GitLab Mattermost Production Installation - Install Mattermost for production environments bundled with GitLab, a leading open source Git repository, using an omnibus package for Ubuntu 12.04, Ubuntu 14.04, Debian 7, Debian 8, and CentOS 6 (and RedHat/Oracle/Scientific Linux 6), CentOS 7 (and RedHat/Oracle/Scientific Linux 7).

For technical questions and answers, please visit the Mattermost forum.