Slack, Mattermost, Dialog Messenger, Zulip, Gitter, Fleep, Flowdock, eXo Platform, Ripcord, Wiggio, Threads for Teams, Kandan, Ziggs, Alterdesk, Jaconda, Protonet SOUL, Hyphen Messaging, Typetalk, GlobalMeet, Filevine are some alternatives to Hack Chat.