Ripcord - A desktop chat client for Discord and Slack
Prosody - Prosody is a modern flexible communications server for Jabber/XMPP written in Lua.
Slack - A messaging app for teams who see through the Earth!
Openfire - Openfire (formerly Wildfire) is a cross-platform instant messaging (IM) and groupchat server.
Done Hui - No need to switch between multiple pieces of software to get through the workday. CHATS: Communicate freely. CALENDAR: Know your team's availability, plan meetings. No more conflicts. TO-DOs: Stay on top of all projects. FILES: All files, one spot.
ejabberd SaaS - Realtime XMPP and MQTT Software and Infrastructure as a Service.