https://rocket.chat/ https://rocket.chat/ built with Meteor and with WebRTC videocalls, is another great open source alternative... The list of current and upco

https://rocket.chat/ https://rocket.chat/ built with Meteor and with WebRTC videocalls, is another great open source alternative... The list of current and upcoming features is quite impressive: https://github.com/RocketChat/Rocket.Chat#features https://github.com/RocketChat/Rocket.Chat#features