<a href="https:&#x2F;&#x2F;rocket.chat&#x2F;" rel="nofollow">https:&#x2F;&#x2F;rocket.chat&#x2F;</a> built with Meteor and with WebRTC videocalls, is another great open source alternative... The list of current and upcoming features is quite impressive:<p><a href="https:&#x2F;&#x2F;github.com&#x2F;RocketChat&#x2F;Rocket.Chat#features" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;RocketChat&#x2F;Rocket.Chat#features</a>