Hangouts
Free
Hangouts is an instant messaging software developed by Google.
Mattermost
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.
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.
Priority Matrix
Commercial
Priority Matrix is a time management software application that is supported on a number of platforms, including Microsoft Windows, Mac OS X, Android, and iOS.…
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…
Glip
Freemium
Glip is fully searchable, real-time group chat; video chat, task management, file sharing app.
Wire
Free
Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser cl…
Threema
Commercial
Threema is an encrypted instant messaging application for iOS, Android and Windows Phone.
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.
Flock
Freemium
Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.
Wickr
Free
Wickr is an instant messenger application.
Compare Slack with alternatives
Compare Priority Matrix and Slack and decide which is most suitable for you.