Arduino : Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers,...
Zulip : Zulip is a powerful, open source group chat application that combines the immediacy of real-time chat with the productivity benefits of threaded conve...
WorkAdventure : Stay connected with your co-workers, by creating your own online workspace to work remotely.
Mattermost : Mattermost is a self-hosted solution for bringing all your team communication to one place, and making it searchable and accessible anywhere
Imagine all your team communication in one place, instantly searchable, available wherever you go. That's Slack.