Freemium

Slack is a cloud-based team collaboration tool.

Open Source

Mattermost is an open source, private cloud Slack-alternative, Workplace messaging for web, PCs and phones. MIT-licensed.

eXo Platform

Commercial

eXo Platform is an open source, standard-based, Enterprise Social Collaboration Platform.

qiscus

Free Personal

Qiscus provide everything you need to power up your app with chats.

Flock

Freemium

Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.

Fleep

Freemium

Fleep enables communication within and across organizations, be it your team chats, project communication or 1:1 conversations.

Flowdock

Commercial

Flowdock is a group chat for teams which integrates with GitHub, Jira, Trello.

Gitter

Freemium

Gitter is an open source instant messaging and chat room system for developers and users of GitHub repositories.

Glip

Freemium

Glip is fully searchable, real-time group chat; video chat, task management, file sharing app.

HipChat

Freemium

HipChat is a web service for internal private online chat and instant messaging.

Let's Chat

Open Source

Let's Chat is a persistent messaging application that runs on Node.js and MongoDB. It's designed to be easily deployable and fits well with small, intimate te…

TribeScale

Free

TribeScale is an All-in-One platform to coordinate your team around what really matters - communication, goals, decisions, tasks and results.

Grape

Commercial

Grape is an REST-like API framework for Ruby. It's designed to run on Rack or complement existing web application frameworks such as Rails and Sinatra by prov…