Freemium

Skype is an instant messaging and VOIP (Voice Over Internet Protocol) client to communicate with people in a distant place.

Viber

Freemium

Viber Free Messenger and Phone Calls.

Mattermost

Open Source

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

Matrix.org

Open Source

Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with…

Hibox

Freemium

Hibox provides task management, business chat and video calls.

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.

Dialog Messenger

Free Personal

Dialog Messenger is a handy and feature-rich enterprise multi-device messenger available for server or cloud.

Hack Chat

Open Source

Hack Chat is a minimal, distraction-free chat application.

Slack

Freemium

Slack is a cloud-based team collaboration tool.

Glip

Freemium

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

Rocket.Chat

Open Source

Rocket.Chat free open source chat solution.

Whaller

Freemium

Whaller allows teams and organizations to create their own internal social networks, meaning no adverts and no data exploitation.

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…