Slack

Freemium

Slack is a cloud-based team collaboration tool.

Discord

Free

Discord is a freeware proprietary VoIP application designed for gaming communities.

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.

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…

Flock

Freemium

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

Zulip

Open Source

Zulip is a chat and collaborative software.

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.

Viber

Freemium

Viber Free Messenger and Phone Calls.

Jitsi

Open Source

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

fluxday

Open Source

fluxday is a user-friendly, free & opensource task & productivity management tool for growing startups.

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…

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…